Schu Smoking!

CMRracing

New member
Ok I am new to karting and just received a re freshen Shu Motor and this is its first start up other than him on dyno and it smokes like crazy .pulled plug and wet with oil and so was top of piston. Is this normal and the rings need to seat or should I be sending it back?I would call but Iam sure he is at THUNDER right now and dont want to bug him..
Any ideas out there?
Thanks
 

Dover Power

Member
No it shouldn't be smoking,, maybe a wisk of smoke when you accelerate but not continually smoke no.. As for rings coming in as you mentioned.. If rings aren't seated then its not making very good hp... I would say first to contact him but feel you will need to send her back...JMO
 

CMRracing

New member
That's what I was afraid of ! Thanks for the answers.
oh and iam running 14cc of oil that is the correct amount right?
 

Kart43

Member
These engines do not require valve seals on either valve they do not smoke if they are removed. A valve seal on the exhaust valve is certainly not required, the manufacturers only put them on the intake because the oil can be drawn down the guide on the intake stroke, all pressure on the exhaust stroke is pushing out of the cylinder therefore oil will not be ingested. There is a very small likelyhood that oil is entering the cylinder by way of the valves, it is usually the head gasket not sealing at the edges next to the oil galley or push rod tunnel. The rings and cylinder have to be in really poor condition to causes excessive smoking, which if this is a fairly new engine is unlikely. I have taken engines off wood splitters and pumps that visually you can see the cylinder wear and feel valve guide slop and they hardly show any smoking or plug fouling, and they just kept churning away.
 

bobbyq

New member
I let engine run on kart for little bit ,see if it clears up ,might have oil in top of head were it probly got turned upside down from the shipping .
 

bobbyq

New member
Yea what I was thinking ,but there usually little still in case after draining, I am thinking that little bit got on top of piston . Why it was shipped . Maybe that's what he seeing . That's why I think he needs let engine run for little bit see if clears up . Maybe let engine cool down and start engine again see it still smoking .
 

CMRracing

New member
Ok here is what I have done I drained oil again and made sure proper amount was put back in started engine and it didnt smoke for the first 3 minutes than it started puffing blue smoke and filling the garage even let it run for 10 minutes at 2500 to maybe seat rings shut it off let cool started and let it run for another 10 minutes same thing ....Did this 5 times each time filling the garage .Now it has been sitting on the shelf since September and than I received it in a kart buy out and have all the paperwork on it and it is spotless so I dont think it has ever hit the track(saying previous owner is telling the truth. I thought about pulling valve cover thinking maybe valve seal also but one of 2 things 1. found out in parts book there no valve seals per say so no need to pull it off just yet .2nd wanted to call mike on monday and get his input also and I didnt want to void or put in any question of me screwing it up.
Buy no means am I dogging or talking bad about Schu Power I just want a little incite on this situation or if someone else has faced this because if its an easy fix I would rather do it myself instead of shipping it back....
And thank you all for your input.
 

DynoDon

Moderator
Find someone who can do a leak down. If you have a lot of leakage by the rings, you will hear it through the breather tube in the valve cover and you will see it in the leak down gauge. Either the builder made a mistake or ( and I am more prone to believe my next statement ) you got snuffed on the purchase.
 

CMRracing

New member
ok the latest did leak down.... it of course leaks down but not through breather at all but through exhaust no matter if valve is open or closed would it be an out of adjusted vale? and would the exhaust valve cause oil to get into the cylinder?
Also did compression test warm and its at 60 psi does that sound about right?
 

DynoDon

Moderator
ok the latest did leak down.... it of course leaks down but not through breather at all but through exhaust no matter if valve is open or closed would it be an out of adjusted vale? and would the exhaust valve cause oil to get into the cylinder?
Also did compression test warm and its at 60 psi does that sound about right?
Does not make any sense that the leak down isn't showing anything by the rings. Even at 2% you should still hear a tiny bit through the breather. With the engine smoking as bad as it is described, there has to be a ring problem and that in itself will cause a bad leak down. If it had an out of adjustment valve it would start hard if the valve was to tight but that will not cause the engine to smoke. The only way an engine will smoke is if it gets oil on top of the piston by means of a loose set of rings or the engine was upset with one of the valves open letting oil flow into the head combustion chamber. My suggestion to you is start the engine outside and walk away from it for a good 15 to 20 minutes. Bring the engine just above idle and let it go for a while. Make sure the oil level is good. 12/14 oz. If there was a bunch of oil in the engine from someone getting it up side down it is going to take a while for it to clean up.
 

CMRracing

New member
Iam baffled also and its out in the driveway running now....I even took the oil fill plug out and no air coming out of there either ... and Iam starting to ? my mechanical ability haha(airplane mech by trade).. looked down the cylinder with scope and man everything is crystal clean . this engine is spot less everywhere even took of tins and looks like new..... will let ya know .I was told by the person I bought the Kart from that this how you can tell its rebuilt and fresh that it smokes like that after being done .I never heard of this and question that logic heck like I said he even gave me the paperwork of everything done new head ,carb, bsp cam, crank bearing and clone rebuild is whats on the paid invoice from SCHU.
 

Chris86

New member
I would just send it to schu power and have him look at it. I bought a couple of clones in a buyout which were built by Jason Brooks at Brooks Racing Engines. Even though the seller told me they were fresh, i really dont like to take peoples word that they are. I got the motor to jason and he revealed to me that they have been ran recently. He went trough them and done some upgrades. Point is the engine builder knows best about his motor. I am glad i sent mine to Brooks because it is a Hoss of an engine and fairly inexpensive to get the answers i was looking for.
 

CMRracing

New member
Definitely Agree Chris and 99% sure Iam going to send it back just wanted to make sure it wasnt an easy fix or something I may have overlooked.
 
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