kenikas

We've been getting quite a few used parts from Power Sports Nation, and have been very happy with them.

I'd agree with what's been said about using the original carb when it's possible, but I've had a few that I haven't been able to find a good kit for. Most of the Chinese knockoffs are pretty hit and miss, but I've had fairly good luck with the ones from Caltric. As has been said they usually need a bit of set up, but for the most part seem to be a little better than most.

Finally getting around to a follow up on this, unfortunately this machine kinda got back burnered and is still in the corner of the garage due to other carb/ignition troubles. But we did come up with a cure for this shifting issue, this is a nylon lined cable, and the Suzuki replacement is surprisingly NOT CHEAP! So we got a serviceable used cable from powersportsnation, that is much smoother than the original. But it still doesn't always completely center when shifting and we're hoping that when we get it running better and ride it around it will loosen up a bit more. My thoughts are that the internal spring on the shaft is a little weak and that's causing part of it, so we just put a couple of "helper" springs on the foot lever, and that seems to have cured it.

Thanks for the ideas Mech, we got looking a bit closer and I think you're probably right on with the bent shaft theory. This one comes out of the crankcase, then goes through an extension of the casting on the generator cover, and it's been well and truly "Bubba'ed" at sometime in the past. The foot lever has been welded on to the end of the shaft! So the only way I can see to properly fix it would be to cut this shaft and replace it and the foot lever, but of course the shaft is a discontinued part, and so far no luck finding a used one 😥. So I think I'll most likely fabricate some brackets to attach some "helper" springs to assist the lever back to the center position, and just ride it.

Yeah I've been at it for going on 40 years, back and forth between fixing 'em and flying 'em. So I've done lots of airframe work, as well as most types of engines from the old radial piston's to turbofans. And yes, the old piston radials are amazing, a bit like working on a giant watch! 😄

I have to agree Mech. It's a personal problem with me as well, I've been an aircraft mechanic for years, and find it nearly impossible to fix something "just good enough" to get by.

That can be a dangerous road to go down! 😆 I have way to many hobbies that started out as ways to possibly make a bit of spare cash to help support them, and they all seem to snowball and end up costing a bunch. But I definitely enjoy them. I find we get to attached to our quad collection lol

We've run into another strange difficulty in our resurrection of our 91 Moto 4 250 basket case. It's running great now, and with the new cylinder & piston we're thrilled with the power this thing has! We searched high and low for a replacement drive shaft boot, but since this style was only used for a couple of years, they are pretty much unobtainium at this point 😥. I was able to fabricate one out of a truck C V joint flexboot that seems to be working well, I'll post a write up on it with pic's when I a few spare minutes. But back to the problem I'm having with the foot shifter, it seems to shift pretty well going up through the gears and goes into all of them, but going back down we have a problem. The foot shift lever sticks down and won't return to the center position until you reach down and bump it up with your toe. It sometimes sticks up when upshifting too, but that's fairly rare. I'm running a straight 40 wt. mineral oil to help break in the new piston rings and flush any crud out of the engine, and plan to change it and the filter in a couple of days but don't think that would effect it. We did have the engine right side cover and spacer off (clutch side ) and had the shift arm, guides & pawl off, but I'm sure I got it all back together right. Any Ideas would be appreciated.

Hi Tin, that doesn't sound foolish at all to me! That's what my grandson and I do for fun, we've been restoring a 91 Moto 4 250 that we got as a basket case a while back. A least yours is all together 😂. But most parts are available with a little scrounging on Amazon or Ebay, and there are quite a few in the salvage yards as well (we've had really good luck with Power Sports Nation), and you can usually get an answer to any problem you run into on the forums here. Look in to downloading a manual for it here, that's pretty much a gotta have. Good luck with it

I usually use Mobil Delvac 75w-90 synthetic in mine, our temperatures here can be 110 F in summer, and down to -10 F in winter. and it seems to work well in all our drive gearboxes. It doesn't hurt that I often get it free from work when it goes past the shelf life for use in our aircraft gear drives!

Wanted to post a follow up to this since we finally found the culprit and got the old beast running. It turns out everything was good with the magneto, so we put it all back together and went through all the wiring and switches again just to make sure and everything checked good per the wiring diagrams and the manual. Still no spark! Tried several different spark plugs, nothing. The guy we got it from had replaced the ignition coil with an aftermarket "racing" coil and the resistances checked "close enough for government work", but luckily the original coil was in one of the misc. parts boxes that we got with it. The spark plug connector on it was broken but we were able to take the one off the "new" coil and use it on the original one, and after cleaning off all the rust and crud on the mounting contacts, it tested perfectly within specs so we bolted it on and hooked it up and nice big fat sparks! So I guess the moral of the story is never throw anything away!

Got to agree, OEM is best for critical parts if or when you can get them! Most of our machines are old derelicts that my grandsons and I have brought back from the dead, and OEM parts are very often no longer available, but Partzilla and Parts Monster have been the best place to find them so far. We do a lot of searching on Ebay and Amazon, but often the parts you get there are chinesium, and a gamble as to whether they'll work or not. We've been getting quite a few used parts from Power Sports Nation, and have been very happy with them.

My grandson and I are trying to resurrect a 91 Moto 4 250 that we got as a basket case a while back, and are having trouble getting a consistent spark out of the ignition system. We've been able to get it to cough and pop a few times, but can't get it to start up and run. When we pull the spark plug out and hold it against the cylinder while cranking it seems to get a few bright sparks, and then they just get weaker and weaker. We've gone through the troubleshooting steps in the manual, and the ignition coil resistances checked ok ( it had a new coil on it when we got it, appears to be an aftermarket one ). The main switch, and the engine stop switch checked ok, so we moved on to the magneto and the source coil, and pickup coil resistances were both within limits. So we ordered a new CDI box off Amazon ( unfortunately the only things we can find are cheap chinese knock offs ), but that didn't seem to make any difference either. But just to give a little more background on this machine, it seems to have been at least partially submerged and not cleaned at some point in it's life. And the guy we got it from had left the spark plug out so the piston was rusted into the cylinder wall. It now has a new cylinder, piston & rings, and we looked everything over and cleaned it up. Back to the magneto, I decided to pull the stator and check it and the magneto rotor for any damage or crud, and that's when I found something that struck me as a bit odd. They seem to be inside the oil bath of the crankcase with the pickup coil and the lower part of the stator sitting in the oil, when I separated the spacer that holds the stator from the crankcase, it drained the oil from the engine. Does anyone know, is that normal? I've been an aircraft mechanic for 40 years and anytime there was oil getting in to the magneto's on an aircraft engine it was time to overhaul them. I've worked on CDI motorcycle ignitions ( albeit many moons ago! ) but they were all 2 strokers, and this one's got me pulling out what little hair I have left! My grandson has a Timberwolf that's fairly close in year to this one, we think, but of course none of the plugs on the CDI (or anything else) match so it's had to swap parts for troubleshooting. Any ideas anyone have would be appreciated

No, it's definitely in the cable. And this one has a winch operated plow. But that was my original thought too, that it was just rubbing somewhere.

Thanks Mech, yep the lever on the case moves like it should when the cable's disconnected. I disconnected it from the shift pedal as well and the culprit is definitely the cable. I'll try and flush it out and run a bit of cable lube through it and see if I can get it to move smoothly.