Adding new motor to my Christmas list

[joshw0000]

Hurry up with that autopsy.
Sounds like the governor internals let loose.

With all the family stuff in the next week or so it might take some time. Here's some shiny yard parts while you wait.

 

[Whitetrashrocker]

Long time damage.

 

[Edwin Spangler]

That jack shaft needs to be there for the chain to line up.

You just flip the clutch if removing the jackshaft. Some minibikes need risers but thats all.

 

[Hellion]

Long time damage.

That's exactly what I expected to see, but one of the worst "spun bearings" I have ever seen. It was a ticking time bomb.

Would love to see accompanying crankshaft journal although there's probably not much to see. Since it is hardened steel the crank can largely recover and be re-used and the aluminum transfer on the journal can be removed with acid and varying grades of superfine emery cloth.....

Wow.

 

[Sparkwizard]

You just flip the clutch if removing the jackshaft. Some minibikes need risers but thats all.

Thank you. You beat me to it. If you run the clutch with the sprocket inboard, they line up fine. Might need a chain tensioner, though, just to keep the long chain from flopping around.

 

[Edwin Spangler]

yea defentily I did the same with mine

How was the accel after that? What tooth count are your sprockets?

 

[joshw0000]

Things have finally slowed down and now it's DISCOVERY TIME!!

It looks like a half @$$ governor delete caused the failure, but here's what I've found so far. I'm still digging.






Yes, that washer and piece of plastic was inside.

I was able to remove the spark plug by hand (no tools).



Not sure if this is normal or if the flywheel isn't tight but look at this movement.

Pushed in:



Pulled out:

 

[joshw0000]

What else do you want to see?

Judging by how it shot out of the engine I'm SUPER lucky. It must've hit the bottom of the fuel tank. And the fuel tank was full (I had just topped it off before the final ride because I thought the issue was it being out of fuel). Had it pierced the fuel tank I probably wouldn't be posting this right now.



Stock flywheel = safety last

 

[joshw0000]

I've got some welding to do before the new motor goes in. I'll probably shorten the kickstand while I'm at it. It's so long the bike won't stand on its own, even with the brand new tires I recently installed.



I've decided to install the Predator I've been building in another thread (originally for my green Baja) and leave the Baja as-is for now.

Speaking of which, I fired it up today for the first time. I wasn't able to run it for long. I had it clamped to my work table but it kept walking off. I still need to dial in the carb, but it sounded REALLY good on the first crank....as in it idled perfectly and responded to throttle ferociously. Kinda makes me worried that something will go wrong with it.

For those who haven't read the other thread, I bought it off of marketplace not running for $80 and it came with a torque converter. It also had a shotty governor delete so I removed it and the oil sensor and plugged the holes. I cleaned up all of the gasket maker the last guy used and put a real gasket on it. I installed 18 lb valve springs @ 003, an aluminum flywheel, new spark plug, new coils @ 003, did tons of cleaning, painted the fuel tank / side cover / pull start cover (not currently on as it's very hard to pull). I installed the VM22 style (not sure what size) carb from the blown motor which has a 105 jet that I installed, and the exhaust from the blown motor. I also polished the exhaust (no porting on either side for this build - maybe next time).

 

[Whitetrashrocker]

I think the bearing was going to gall and seize on you if that governor didn't fail first.

We should sticky this for all the world to see why you should always remove the internals and not just bypass the governor.

 

[Whitetrashrocker]

And the crankshaft end play is what you're seeing. It won't be correct until the cover is on. That's when you check.

 

[Hellion]

Wow, absolutely fascinating and a massive photo dump is icing on the icing. This is how engines die, at the hands of Bubba and bad info (just bypass the governor, bro) on the internet. They always say "oh it's fine" and it is ....for a while.



"Beautiful" chaos in those photos.

 

[Hellion]

I'd part out everything that's not broken on that motor.

shorten the kickstand while I'm at it. It's so long the bike won't stand on its own, even with the brand new tires I recently installed.

What tire size was on it before and what's on it now? Suspect they are a bit shorter than stock which makes the kickstand too long.

Kinda makes me worried that something will go wrong with it.

We've been beating the drum on the sporty cone filters not actually filtering anything (except bugs). Only thing I'd feel safe using a cone filter on is a mud motor or long tail marine engine. Bodies of water are very dust and particle-free for obvious reasons. I understand some boat engines don't even have an air filter...

 

[joshw0000]

I'd part out everything that's not broken on that motor.



What tire size was on it before and what's on it now? Suspect they are a bit shorter than stock which makes the kickstand too long.



We've been beating the drum on the sporty cone filters not actually filtering anything (except bugs). Only thing I'd feel safe using a cone filter on is a mud motor or long tail marine engine. Bodies of water are very dust and particle-free for obvious reasons. I understand some boat engines don't even have an air filter...

I'm not 100% sure which model it is. The plastic crankshaft is throwing me off. That's usually found in 224's and some older 196's.

19X7-8. The old ones were completely bald from being driven on asphalt. I put the same size on with fresh tread, actually raising it some. The kickstand is still too tall. I've found posts online where other Coleman's had the issue.

I thought about getting a sponge to go over it.

 

[panchothedog]

All of your pictures are fantastic advertising for the ARC billet rod. Hope you put one in your new engine.

 

[Thepartsguy]

I don’t know the gear ratio of the jackshaft bikes but despite the fact it is a ho-hum fixed ratio, the *jackshaft will get you there* and won’t eat a belt when you’re 5 miles from home. I wonder if anyone in the hobby keeps the jackshaft intact (or intact but tweaks the tooth count) on a performance-minded build? Performance doesn’t always mean the road to Mach 1. Jackshaft gives you a better hole shot, bottom end torque but the top end is strangled a little or a lot. Just pontificating…..



Reminds me to put a tiny tach on everything I own. Without that, it’s just subjective or “by the seat of one’s pants”

The jackshafts being side mounted or engine plate style can be re-geared for lots of speed. I had a circle track in the front yard and it was a ton of fun.

 

[Hellion]

The jackshafts being side mounted or engine plate style can be re-geared for lots of speed. I had a circle track in the front yard and it was a ton of fun.
View attachment 159427

What’s the tooth count on all those sprockets, Partsguy?
I want to plug them into a speed calculator that has the jackshaft option.

Max rpm on your engine?

 

[joshw0000]

I bent the kickstand and it now stands on its own. Thoughts? Leave it as-is or bent a little more? I feel like it might need a little more.

 

[Hellion]

Thoughts? Leave it as-is or bent a little more?

I can hardly tell its bent. Question: can a clumsy passerby bump it and knock it over? I think it needs a healthy lean like any motorbike.

 

[joshw0000]

I can hardly tell its bent. Question: can a clumsy passerby bump it and knock it over? I think it needs a healthy lean like any motorbike.

Yea, they could. I'm gonna bend it some more before I finish