Arizona

I ran auto repair shops for over 23 yrs so I can relate. Something as little as crank

seals which were only 25 bucks but require a lot of labor. Same with piston etc. 

I always keep track of the money spent on parts, batteries and tires are the worst. 

as far as hourly rate I never gave it much thought as I do it to enjoy it but if I did 

I would figure in about 30 p/hr  The going rate is probably 60 - 100 at a stealership

and the mechanic never sees that kind of money. Az

Well today I said farewell to my Polaris. I know that thing inside and out but sold it today ended up getting 1700.00

for it so I wont miss it that bad lol. Had less than 300.00 invested but a lot of labor. Each one I do I learn something. 

And each one I like and would like to keep but the garage fills up pretty fast. I got one torn apart and plan on picking

up 2 this Saturday. Gonna keep me busy! Az

Yes I agree on a little high, but needed something to work on as I am out of vehicles. 

Have done about 9 of these things and always turn a great profit.  More of a hobby

as I enjoy bringing them back to life, a challenge and some times a pain but over all 

keeps me out of trouble.  Will see how it turns out. Az

I think I paid too much but needed another challenge. 350.00 The only positive it does have a winch

(don't know if it works) These things keep me busy and actually have been making pretty good profit

also. Stay tuned Az

Well im at it again, took about an hour drive Saturday and made a deal on this old honda. 

Might be restorable. Tires pretty dry rotted, mastercylinder broken glass and probably full of water. 

Handed me the carb he rebuilt (oh no) He said ran about 6 months ago but when we pushed out of his

field there was a tree growning through it. See pic.  Missing some parts, also missing the intake. Motor is not

locked up, Has piece of plastic crammed in the head since no carb there for months. Brake cables bad, etc. Thats

part of the fun. Im sure I will be posting some questions later for you all. Stay tuned Az.

Update on the Explorer. After tuning the carb, jets, choke, etc also replaced crank seals.

finally got it back together and runs great. One other thing, while running it I lost the neutral/Reverse indicator light.

Thought it had to do something with the key switch which came loose but finally figured it out. Ended up being a 

loose connection on the connector on top of transmission, so if you get this problem check both those connectors. 

I only have about 250.00 invested in this thing, might keep it as its a 4 wheel drive and could

use it with my trailer for work around the property

Have it all back together, also replaced the supply line and filter from the 2 stroke motor reservoir and 

the tube from the pump to the carburetor. Seems like both were leaking. Took about a month to get 

those parts from Partzilla. I will see if it starts later. Finally have it mostly back together. Just have to turn 

on the fuel and see if it starts on its own. 

After all assembled, hooked up gauge gave it a pull and got about 125 psi by pulling

on the rope. Got it all back together and wouldn't run, found out he really screwed up the carb.

have gone through it several times, Got it to run but will only start with starting fluid. Once its hot it will 

stay running. Let it cool down wont start on its own. Have checked the choke system, raised float level till almost

floods. Still same problem. Installed larger jet and would run a lot better still no cold start. Raised the metering rod the highest

and it starts when cold but boggs out due to too rich condition at half throttle. 

I have tried the metering rod on every position. If I put it where it runs good it wont start when cold.

Finally I decided to tear out the starter as its bad anyway. While in there I replaced both crank seals as 

I have heard they can cause a lean condition and since im in there already...…… well you know, its all about

the fun. 

Well I took some time off, Finally got around to have it machined. Had to go .5 over and it cost me 128.00 for the labor. 

Then cost about 100 for the piston kit gasket etc. Installed the piston on the crank, was fun trying to manipulate the cylinder

on the piston and compress the rings while motor still in frame, kept running into frame, linkages, shifter etc. Finally after several

colorful words got it in there. 

Did you ever fix this problem?

Might check with Laval, seems he has some experience with Yamaha and their reverse. 

On mine I had to loosen up the foot pedal adjustment, I guess it needed to move more.

I adjusted my rear brakes and that's what caused the problem, after loosening them up 

it worked again, Also had to be in 1st in order to go into reverse. Seemed to be a problem

an each Yamaha I have owned. Just got rid of one and same issues. 

no coolant, air cooled unless im missing something. 

Cant seem to find a cylinder for sale, Only one I found 

was 400 plus.  The cyl wall is definitely gouged. 

The bearing looked ok but would replace if repairing. 

Trying to figure motor size, says nothing on plastics, or the title, only numbers are EC25PFX 01 Which

are on the cylinder. The vin code is 4XAAG25C312459874

Tried vin search but still doesn't show motor size. 

Ok, so not doing anything today so figured I would look inside.

Finally get the head off and actually looks good. Was expecting an exploded

piston. Got the cylinder off and that's when I saw the damage. Hopefully it can 

be bored instead of replaced. Do you thing it was starved of 2 stroke oil? The previous owner 

had removed the carb and tried to fix it and had problems after that. I did see the oil line was connected

to the carb and the oil tank is full so I am guessing. The damage looks like it had no oil but what do I know. 

Any thoughts? Az

was going to adjust the clutch but lucky me the 300 it looks like you have to take off the case to do that. 

There are 2 covers on the clutch side, took both off nothing there, looks like adjustments are internal. 

May put it off until I finish the Polaris.  Az

Ok, so its been a while on this bayou 300. It runs great but has a tapping noise from the motor.

Gets worse as it warms up. Runs smooth, but that noise is pretty loud, I know its hard to identify

motor noises but thinking may need piston. Gonna eventually pull it apart after done with my other

project. Not sure what rod bearings sound like on a atv but to me it sounds like piston or wristpin. 

What you think.  You tube video here--------  

So few months ago I acquired a 01 Explorer 4x4 (think its a 350 but not sure) 

Anyway the owner said it started reving very high, shut the key off and still kept running 

until finally he shut off fuel and it finally died. During the run away he said the exhaust got 

red hot and has melted plastics to prove it. Said some thing flew out the tail pipe, I kinda figured

it was the top of the piston. Anyway finally got around to looking at it (have a lot of other projects in the works)

and checked the compression, Shows about 40 psi. Can hear air coming out the carb while rotating the motor over. 

Gonna pull it apart eventually, don't hear any noises or binding in the stroke, You think the piston came apart? 

any horror stories of these and is it worth my effort and money? Don't really have any money in it yet. Thoughts? Az

Well im looking into a used oem carb. The online engine builder says he has a few and should call me back. 

also found 1 on ebay but looks pretty rough. Ign. coil was putting out about 28kv

I sure find the weird ones! Az

talked to an atv engine builder and he said you will get different compression readings

between no throttle and full throttle. Should be checked at full throttle. I checked the online 

manual and it says check at wot

I agree weird readings. But they are repeatable. Just depends if throttle is open or not. 

Would think cam problems would be constant. I cant think of anything that would make

them change due to throttle angle. Im stumped. Any Yamaha motor builders out there that

have ideas?  

On a second note, after screwing with the second carb I got it to go quite a bit faster but still not right.

I can floor it in neutral and it wont redline. Just revs about half of what it should be. Pretty odd as it 

idles pretty smooth and starts pretty easy. Hoping for some knowledge on the motor Az

Yes the compression changes every time I either open or close the throttle. 

 Never heard of 

the readings changing with throttle angle. It will read 125 as long as throttle is opened.

If not it reads about 85psi. The motor runs super smooth at idle and doesn't smoke. 

Any ideas what I should do with it or just leave it alone?  Now second thing. I do not have the

oem carb. Should I try the jet kit on the new Chinese carb? or wasting my money? Az

Well was going to tear it down today but double checked a few things

rechecked compression, right at 85psi then rechecked compression with

throttle wide open and I get 125 psi. Double checked and confirmed with throttle

open 125 psi. so I assume the motor is not the issue.  Still looking at the carb as it 

feels like a carb issue. Similar to problems with the Kaw bayou 300 I had. So gonna 

set the valves before I put it together, Since I don't have original carb and have tried 

2 Chinese carbs, should I try a jet kit and install in this carb? If so what ones do you have

the most luck as far as accuracy with?    Might also see if ign. coil is putting out enough

volts, I am assuming it should at least put out 20kv Any other ideas? Thanks Az

usually a good smack to the fuel bowl with a screwdriver handle will bust it loose. 

So my latest find is a Moto 4 250. Looked in good shape, started right up but would backfire and die upon acceleration but you 

could get it to go if you were good with the throttle. I figured it was the carb. was a brand new Chinese carb, he didn't have original.

I took it apart and cleaned it, only thing I found was some debris in main jet and the main adjustment on bottom was at 41 turns. Cleaned 

it out and set at 2 turns, re installed. Starts up, runs better actually drove it but seems really sluggish, once I hit 3rd gear could barely pull

it. Rechecked everything, even ordered a new carb as I had this problem with another atv but still same problem. Now I pull it apart and 

decided to check compression, I show only 85 psi. I checked valve adjustment (after aligning up cam gear to mark on case). to make sure not too tight still right at 85 psi. 

I assume I need to pull the head and look at the valves, Any ideas I am missing something?  motor does not smoke but is super sluggish. 

The specs I find are off the downloaded manual of a 94 but figure should be the same. It states compression standard is 128  and Minimum is 114 and Max is 142

Any other Ideas before I tear it down? Thanks in advance Az