Another one back from the dead (1997 King Quad 300 LT-FWDX)

[Hagbard]

Yeah, so that would make the top one for the petcock, white plastic one for the pump, because I left all the OE lines in place, and labeled for where they attached to the stock carb. The only one I didn't re-use was that top one, and I switched out to a non-vacuum petcock.

[coyote56]

well I just ordered a new petcock because the old stock one is all gunked up. I see a pump line coming from it but... only one? There is another? I guess you guys are talking about the pump that is next to the battery box.

I just ordered a new petcock off ebay with a pump built onto the back of it.... maybe I don't need that pump next to the battery box anymore?

[JustRandy]

49 minutes ago, coyote56 said:

well I just ordered a new petcock because the old stock one is all gunked up. I see a pump line coming from it but... only one? There is another? I guess you guys are talking about the pump that is next to the battery box.

The pump is in the front somewhere.  It could be by the battery box, but I'm not sure.

49 minutes ago, coyote56 said:

I just ordered a new petcock off ebay with a pump built onto the back of it.... maybe I don't need that pump next to the battery box anymore?

Yeah if you have a new pump then you don't need the old one.

[coyote56]

we will see.... I just hate guessing. Things will probably make more sense when I get the front rack off and the plastic and can see what all is going on under the hood

[JustRandy]

Just now, coyote56 said:

we will see.... I just hate guessing. Things will probably make more sense when I get the front rack off and the plastic and can see what all is going on under the hood

Yeah that will help.  I haven't had it apart in 9 years so it's hard for me to remember what anything looks like under the hood.

[Hagbard]

11 hours ago, coyote56 said:

well I just ordered a new petcock because the old stock one is all gunked up. I see a pump line coming from it but... only one? There is another? I guess you guys are talking about the pump that is next to the battery box.

I just ordered a new petcock off ebay with a pump built onto the back of it.... maybe I don't need that pump next to the battery box anymore?

One is an actual fuel PUMP the petcock just has a vacuum diaphragm that shuts off fuel if there’s no vacuum. You definitely need both. 

[coyote56]

OK so I was able to confirm today from Schneids15's youtube channel... the plastic and the ring finger connections are your vacuum line hook ups. He has his fuel pump connected to the plastic and the petcock to the ringer finger outlet. He said it didn't really matter though, either way would work. The pointer finger outlet is a breather vent.

Edited November 4, 2021 by coyote56

[Hagbard]

On 11/1/2021 at 12:30 AM, Hagbard said:

Yeah, so that would make the top one for the petcock, white plastic one for the pump, because I left all the OE lines in place, and labeled for where they attached to the stock carb. The only one I didn't re-use was that top one, and I switched out to a non-vacuum petcock.

Right. Like I said here. I still hate that POS carb. Thinking a PWK28 is on deck. 

[Hagbard]

Finally got to go see my KQ out at the farm where I left it a month ago when my radiator blew. Spent about 15 minutes cranking and choking and running down the battery before I decided to back off the intake valve a hair. Fired right up first crank afterwards. Carb doesn’t like the colder air though, so it didn’t want to do much to get out of its own way.

[Hagbard]

On 11/1/2021 at 10:30 PM, coyote56 said:

we will see.... I just hate guessing. Things will probably make more sense when I get the front rack off and the plastic and can see what all is going on under the hood

Any luck getting this apart and figured out? I had a really fun time chasing down corrosion and loose connections in the harness. Worth cleaning the grounds too.

[JustRandy]

On 11/4/2021 at 9:27 AM, Hagbard said:

Finally got to go see my KQ out at the farm where I left it a month ago when my radiator blew. Spent about 15 minutes cranking and choking and running down the battery before I decided to back off the intake valve a hair. Fired right up first crank afterwards. Carb doesn’t like the colder air though, so it didn’t want to do much to get out of its own way.

I went through that process of adjusting the lash to get it started for at least a year before I finally fixed it.

Actually what happened is I burned up all the oil (yeah all 4 qts) and spun a cam bearing so I had to replace the cam and head and cover.

No, actually what happened is a friend's truck somehow ejected the pin that holds the clutch hydraulic line in the slave cylinder so it was dumping oil and no way to fix it without removing the tranny, so since I was all greasy from helping him I decided to do my quad and that's when I discovered I ran it out of oil lol.  I never thought it was possible to burn up 4 qts of oil between oil changes.

[Hagbard]

Been doing a little puttering around with a Blaster cylinder, polishing and smoothing out casting defects,

matching the exhaust port to the gasket,

smoothing the transitions between the transfer ports, and was reading a little of Eric Gorr’s writing on 2 stroke tuning.

 

Since I have this spare to fiddle with I decided to try my hand at milling out some “Boyesen ports” - essentially lower boost ports between the transfers and the intake just behind the reed cage.

Ideally they are around .5”, I chickened out after getting to .375+/- without fu***** it all up, and called it a day. 

 

In theory these increase scavenging at the cost of some velocity- aka more low-mid brap with less top speed. Going to start out with some Boyesen fiberglass reeds and see how they fare. 
 

And THIS time I’m going to make it a point to remember to clear the transfer ports of honing pumice BEFORE firing up the engine and frying the new rings. 
 

¯\_(ツ)_/¯ 

Did I mention I found an ‘87 RM80 roller for free? Have a DS80 motor that won’t fit in it, so yet another thing to hunt for in vain lmao

[coyote56]

On 11/5/2021 at 11:00 PM, Hagbard said:

Any luck getting this apart and figured out? I had a really fun time chasing down corrosion and loose connections in the harness. Worth cleaning the grounds too.

Well the wiring harness is good. It will start by pushing the start button so I have no issues there. However, given the huge amount of smoke it produces, oil coming from the exhaust and around the head.... I don't think there is any hope left that it will not need a top end rebuild. Luckily the same guy that posted the carb video has one of him rebuilding a king quad's top end and as I said... they are pretty much the same bike just 50 ccs difference.

I haven't decided if I want to wait until I get it all broken down to see what is going on in the bore before I order my rebuild kit or if I should just do it now with a .5mm bigger piston and just plan on taking it to be bored out.. opinions?

[Hagbard]

6 minutes ago, coyote56 said:

Well the wiring harness is good. It will start by pushing the start button so I have no issues there. However, given the huge amount of smoke it produces, oil coming from the exhaust and around the head.... I don't think there is any hope left that it will not need a top end rebuild. 

 

Check that it's not just your valve inspection caps seeping oil right onto the exhaust like mine were. there was years worth of seepage crud all around the exhaust port and all over the pipe and heat shield. Took a lot of degreasing and power washing to get it cleaned up, after that the smoking was minimal.

If you do the top end, I'd say the valves are probably going to be your main concern. Just based on the conversations I've had here with Randy, my plan is to replace valves, seals, and either ream or replace guides, lap valves, and if need be have the seats re-cut. I honestly don't really suspect much ring wear at all, but it seems to be a relatively minor expense on top of everything else, so I might as well do the piston too, new rings and wrist pin bearing couldn't hurt. I'd wait and see the condition of the cylinder sleeve before ordering any rings or a new piston, personally.

 

[coyote56]

1 minute ago, Hagbard said:

Check that it's not just your valve inspection caps seeping oil right onto the exhaust like mine were. there was years worth of seepage crud all around the exhaust port and all over the pipe and heat shield. Took a lot of degreasing and power washing to get it cleaned up, after that the smoking was minimal.

If you do the top end, I'd say the valves are probably going to be your main concern. Just based on the conversations I've had here with Randy, my plan is to replace valves, seals, and either ream or replace guides, lap valves, and if need be have the seats re-cut. I honestly don't really suspect much ring wear at all, but it seems to be a relatively minor expense on top of everything else, so I might as well do the piston too, new rings and wrist pin bearing couldn't hurt. I'd wait and see the condition of the cylinder sleeve before ordering any rings or a new piston, personally.

 

 

[Hagbard]

17 minutes ago, coyote56 said:

 

I stand corrected. =D Unless thats just all pouring through the valve seals =P

[coyote56]

Just now, Hagbard said:

I stand corrected. =D Unless thats just all pouring through the valve seals =P

😆 I was hoping I wouldn't have to. I'm not a mechanic but... the four wheeler was free so... it's a good learning experience. If I screw up to bad, I will just load it up on the trailer and drag it down to Suzuki. I am concerned about the back end, I got the wheels off and it's not the brakes locked up. Something is going on inside the transmission so I am going to have to take that cover off and see what is going on inside. I am gonna soak her down good with WD-40 this afternoon before I leave for work for the week. Hopefully next weekend I can get a lot more accomplished on it.

[Hagbard]

2 hours ago, coyote56 said:

😆 I was hoping I wouldn't have to. I'm not a mechanic but... the four wheeler was free so... it's a good learning experience. If I screw up to bad, I will just load it up on the trailer and drag it down to Suzuki. I am concerned about the back end, I got the wheels off and it's not the brakes locked up. Something is going on inside the transmission so I am going to have to take that cover off and see what is going on inside. I am gonna soak her down good with WD-40 this afternoon before I leave for work for the week. Hopefully next weekend I can get a lot more accomplished on it.

I have had really great results with using a 50/50 mix of Acetone and ATF as a penetrant for rusty hardware. It creeps into spots other stuff doesn't seem to touch, the acetone evaporates and leaves behind some of the slickest stuff known to man.  Also love PB Blaster's CSP Corrosion Stop and Prevent spray, it seems almost waxy and clings where you put it. Almost like fogging spray for boats.

And I'm in the same boat skill-wise. I've turned wrenches on my own cars, and friends stuff, but never professionally. I got lucky and scored a really nice set of tools on the cheap, which helps a little bit, but without google and solid advice from forums like this, I'd be lost. Having the shop manual helps too. Between this place and youtube, (Schneids is good stuff) there isn't much you can't tackle. I If you need a copy of the manual, let me know. If you need valve seats cut, I know a guy in your neighborhood with a nice set of cutters.

 

[coyote56]

5 hours ago, Hagbard said:

I have had really great results with using a 50/50 mix of Acetone and ATF as a penetrant for rusty hardware. It creeps into spots other stuff doesn't seem to touch, the acetone evaporates and leaves behind some of the slickest stuff known to man.  Also love PB Blaster's CSP Corrosion Stop and Prevent spray, it seems almost waxy and clings where you put it. Almost like fogging spray for boats.

And I'm in the same boat skill-wise. I've turned wrenches on my own cars, and friends stuff, but never professionally. I got lucky and scored a really nice set of tools on the cheap, which helps a little bit, but without google and solid advice from forums like this, I'd be lost. Having the shop manual helps too. Between this place and youtube, (Schneids is good stuff) there isn't much you can't tackle. I If you need a copy of the manual, let me know. If you need valve seats cut, I know a guy in your neighborhood with a nice set of cutters.

 

I may have gotten lucky... there is another guy here in my area selling an identical four wheeler for a few hundred bucks. The one he has was stolen but recovered and the thief took carb and battery off of it. If it is still there next weekend when I get home, I will be picking it up. He says it was running next year.. if so I may just slap my good parts on it and then decide rather to just slowly rebuild the current bike or just keep it around for a parts bike. Figuring out what is going on in the transmission is more than a little worrisome to me.

[JustRandy]

On 11/6/2021 at 11:33 PM, Hagbard said:

In theory these increase scavenging at the cost of some velocity- aka more low-mid brap with less top speed.

I don't know much about 2-strokes but scavenging in 4-strokes is a function of velocity of air.  I make my ports smaller (and uniform) to increase velocity which increases scavenging and low-midrange power (at the sacrifice of top end due to the restriction of the smaller ports).

The faster I can get the air moving the more of it will fill the cylinder while the piston is doing nothing at the bottom of the stroke.  It's supercharging effect similar to an expansion pipe on a 2-stroke.

[JustRandy]

15 hours ago, coyote56 said:

 

Holy smokes man!  Are you sure you don't have oil in the gas? lol

I think I'd want to tear it down to assess the damage before sinking money into it.  Someone could have ran it out of oil.  You could be looking at a new head, cam, rockers, piston, rings, and bore job assuming the rod bearings are still ok.

But at minimum I think it's fair to say you need new rings.

7 hours ago, coyote56 said:

I may have gotten lucky... there is another guy here in my area selling an identical four wheeler for a few hundred bucks.

I may just slap my good parts on it and then decide rather to just slowly rebuild the current bike or just keep it around for a parts bike.

That's a good idea having a spare one because I suspect you'll be spending a fortune rebuilding that smoker.

7 hours ago, coyote56 said:

Figuring out what is going on in the transmission is more than a little worrisome to me.

Me too.  Kinda makes me wonder if it ran out of oil.

I burned through 4 qts of oil in mine but luckily I caught it in time before something serious happened.

[JustRandy]

13 hours ago, Hagbard said:

I have had really great results with using a 50/50 mix of Acetone and ATF as a penetrant for rusty hardware.

I've heard a lot lately about ATF as a penetrant.  I'll have to try it.  I've been using PB and it's hard to tell if it does anything.

13 hours ago, Hagbard said:

PB Blaster's CSP Corrosion Stop and Prevent

May as well add a can of that to my collection.

13 hours ago, Hagbard said:

Between this place and youtube, there isn't much you can't tackle.

Yep, I found videos on how to fix my washing machine, riding mower, push mower.  Practically anything I have someone has a video on how to fix it.

I don't really have an issue paying people to fix things, but it's hard to trust they will do it right.  I had 2 pros look at my heatpump before fixing it myself, which was just putting a jumper from an old harddrive on the circuit board.  It had something to do with the low-side pressure which the circuit diagram said was optional, so I just turned it off and that fixed it.  No clue how many pros I'd have to pay before I found one who could fix it.  Replacing the board didn't fix it because the new board also didn't have the jumper.  Eventually one of them would have resorted to selling me a whole new unit since I'm sure none of them would have discovered a simple jumper.  That was close to 10 years ago and it's still going.

[JustRandy]

Back in 2008 somebody slapped these links on the big thread at atvconnection

http://mototuneusa.com/power_news_--_think_fast.htm

http://mototuneusa.com/power_news_--_homework.htm

http://mototuneusa.com/power_news_--_the_2007_superbike.htm

http://mototuneusa.com/power_news_--_supersonic_nozzle.htm

http://mototuneusa.com/power_news_--_success_stories.htm

Can't believe that site still works.

Can't believe that was 13 years ago.

[Hagbard]

8 hours ago, JustRandy said:

I don't know much about 2-strokes but scavenging in 4-strokes is a function of velocity of air.  I make my ports smaller (and uniform) to increase velocity which increases scavenging and low-midrange power (at the sacrifice of top end due to the restriction of the smaller ports).

The faster I can get the air moving the more of it will fill the cylinder while the piston is doing nothing at the bottom of the stroke.  It's supercharging effect similar to an expansion pipe on a 2-stroke.

I don't profess to know a whole lot either, but I see nothing but respect for Eric Gorr and Edvind Boyesen when it comes to smokers. Also, from the early-to-mid-90's on, you see them being cast into new OEM cylinders. The earliest how-to's you see about them are mainly for retrofitting older bikes of the same model without buying a new jug from the stealership, then other folks caught on and started modding older bikes in the same manner. They're also fond of using JB weld to build up the jug, but on the outside corners, to achieve 1/2" bore for the boost ports. My 3/8" ones could probably be enlarged by another 2mm but I'd just as soon not drill through the side either. I'm probably about 1.5mm away from the sleeve as it is, so erring on the side of caution seems prudent, as I'm not building a race bike. If it pans out, I'll be happy, if not, it's no big loss. Chinese jugs are cheap. 

5 hours ago, JustRandy said:

Back in 2008 somebody slapped these links on the big thread at atvconnection

http://mototuneusa.com/power_news_--_think_fast.htm

http://mototuneusa.com/power_news_--_homework.htm

http://mototuneusa.com/power_news_--_the_2007_superbike.htm

http://mototuneusa.com/power_news_--_supersonic_nozzle.htm

http://mototuneusa.com/power_news_--_success_stories.htm

Can't believe that site still works.

Can't believe that was 13 years ago.

OMFG my eyes. As soon as I saw the phrase "AltaVista search engine" I knew it was going to be a winner LOL.  It's a hell of a concept, and I'm curious to see a dyno readout for one of his motors vs a stock cylinder.

[JustRandy]

AltaVista brings back memories of when google wasn't evil lol.

He has dynos posted on those pages and claims something like 5% more HP.  I'd expect less gains on higher revving engines like DOHC crotch rockets.  Gains should be higher in the long stroke 250s, which can't rev high enough to be choked off by small ports so nothing is really lost.

Half the stuff you're talking about concerning 2-strokes I can't even conceptualize in my head to know what you mean.  What the heck are boost ports? 

The only thing I know is the general physics and colloquial use of words wherein scavenging usually means the exhaust draws in more intake by virtue of inertia, which is a function of velocity and mass.  Maybe it has some other meaning in the context of 2-strokes.

After (evidently) 13 years of thinking about it I'm pretty confident that porting for velocity is the way to go in the 4-stroke arena, especially if the engine is constructed such that the piston dwells a lot at the bottom (and the reason why I like the longer intake duration of the 250S cam which takes advantage of the inertia of the air in the intake port).

Basically the air is accelerated by the downstroke and, while the piston is not moving at the bottom, which is quite a long time in terms of degrees of crank rotation, the air continues to rush into the cylinder by inertia which supercharges the cylinder.  What normally would be 300-400cc of air is squeezed into a 250cc cylinder (ie supercharging) because of that velocity.

If the ports are too large to achieve the necessary velocity to have the inertia to supercharge the cylinder then as the piston dwells at the bottom, nothing happens and the extra duration of the 250S cam adds nothing; the intake valve may as well be closed.

But the opposite will be true at high rpms since the piston moves down so fast that it can't accelerate the air fast enough to fill the cylinder because the port is too small.  So tuning an engine for high rpms necessitates bigger (and shorter) ports, which makes it a dog at lower rpms because of the loss of velocity.

Analogous to subwoofer ported boxes the port length and diameter determines the resonant frequency of the engine (where cylinder pressure will be highest or internal pressure of the speaker box is highest).  And the dB dropoff is really sharp below the resonant frequency of the box (because the port and speaker are out of phase and cancel each other) and the same is true with engines.

Scavenging in a 4-stroke would once again be a function of velocity since the exhaust gas rushing out begins drawing in the intake charge during the valve overlap.  If the exhaust port is too large then nothing will happen during overlap (maybe that's why exhaust valves are always so much smaller than intake valves).

Scavenging in a 2-stroke, as I understand it, is when the exhaust draws the intake charge all the way through the engine and into the exhaust pipe, then bounces off the narrowing of the expansion chamber and rushes back just in time to squeeze back in through the exhaust port before it closes which supercharges the cylinder.  It's pretty cool, but only happens at a narrow band of rpms (and why they call it a power band).  How the internal porting affects all that is out of my understanding except for the generalities of velocity and inertia.

Tuning an engine to be a screamer is pretty fruitless in my opinion unless you're designing F1 racers.  Banshees are really good at throwing dirt into the next county but kinda suck at actually winning drag races because they have no grunt to hookup the tires and get going.  And that's really evident when watching souped up muscle cars getting clobbered by stock Teslas which have mountains of lowend torque.  The big engines are frying the tires while the Tesla is moving down the track.

[coyote56]

good news... I managed to get most of the afternoon off so I went and picked up the other bike. It is in far better condition than the one I currently have... other than the seat being completely destroyed. I didn't have much time to work on it tonight but I did get the seat off to do some poking around. The previous owner was not kidding about the thieves. They must have only stolen the bike for the carb, they cut every line going to it off except for the choke cable. I guess they took the time to unscrew it. However the broke the plastic fitting to the vacuum pump off in the line, so it was nice of them to mark it for me. The throttle cable they just cut, so I am ordering one now. They also stole two of the shifter knobs and the shifter panel on top of the gas tank. Looking like this one may be good to drive after just swapping over the carb from the old bike, flushing out the gas lines, new spark plug, oil change and hook up the battery. That would be a much needed break. It has about 900 miles on the odometer. I plan on getting her going and then starting to break into the old bike, should be a little easier now that I have another reference behind me other than the online parts schematic. The back plastic does have a big crack in it, I can patch that with a piece of aluminum and some rivets.

 

Edited November 9, 2021 by coyote56

[Hagbard]

7 hours ago, JustRandy said:

 

Analogous to subwoofer ported boxes the port length and diameter determines the resonant frequency of the engine (where cylinder pressure will be highest or internal pressure of the speaker box is highest).  And the dB dropoff is really sharp below the resonant frequency of the box (because the port and speaker are out of phase and cancel each other) and the same is true with engines.

 

Scavenging in a 2-stroke, as I understand it, is when the exhaust draws the intake charge all the way through the engine and into the exhaust pipe, then bounces off the narrowing of the expansion chamber and rushes back just in time to squeeze back in through the exhaust port before it closes which supercharges the cylinder.  It's pretty cool, but only happens at a narrow band of rpms (and why they call it a power band).  How the internal porting affects all that is out of my understanding except for the generalities of velocity and inertia.

 

The analogy is quite apt, it's a shockwave that's at work inside the resonator pipe, and as it pushes the charge of fuel and air back into the cylinder, it acts like an invisible valve preventing the charge from escaping.  There's free software available for determining the dimensions of a 2-stroke pipe based on displacement and targeted RPM's of the powerband. I watched a video of some guy in Sweden making one. It seemed... involved.

[Hagbard]

12 hours ago, Hagbard said:

The analogy is quite apt, it's a shockwave that's at work inside the resonator pipe, and as it pushes the charge of fuel and air back into the cylinder, it acts like an invisible valve preventing the charge from escaping.  There's free software available for determining the dimensions of a 2-stroke pipe based on displacement and targeted RPM's of the powerband. I watched a video of some guy in Sweden making one. It seemed... involved.

Finland, my bad.  Make sure you turn on CC

 

 

[JustRandy]

Hey that's great!  Nice back tires too!  With only 900 miles that's a much better deal.

On 11/8/2021 at 8:27 PM, coyote56 said:

They must have only stolen the bike for the carb,

Wow man the carb was the first thing I wanted rid of.  I can't imagine stealing a quad for that.  They may as well have taken the seat too lol

I bought one of those quads once and on the way to pick it up the guy said it caught fire and melted everything.  By that time I was almost there so I decided to get it anyway for a reduced price.  After I scavenged parts off it I made a grader out of it that tows behind my other one to smooth out my trails.

 

[JustRandy]

On 11/9/2021 at 8:27 PM, Hagbard said:

There's free software available for determining the dimensions of a 2-stroke pipe

It's amazing that there are people smart enough to do that.  I always stood in awe of the LEAP software  https://www.physical-lab.com/products/linearx/cae-software/leap

But between using speaker software and engine software I've come to the conclusion that nothing beats real world tinkering.  Software can get you in the ballpark and give understanding how the variables interconnect.