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Old 04-30-2010, 04:25 PM
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Default Engine problems,need opionions

Ok guys i have an issue

Last time i went out on my Nova +4 it sounded like the rear bearing was going, i was trying a 9901 pipe and i was told it makes it sound bad so i wasnt to worried, i ran all day, even a 30 min main no flame outs, but when i came home i wanted to make sure so i went back to 9853, the sound was still there, i also went 3 glow plugs within 30 min, figured the bearings went bad even tho i just changed them a gallon ago. I tore it apart today, looked at the bearings, o rings, and p/s. Bearings are great, o rings are great no tears, and the piston and sleeve have no scarring of any sorts. the internals actually look good for the amount of fuel that has on them.


I was wondering if anyone had any idea what could be the issue, i know its hard to do this online thats why im trying to get ideas. I dont think there is an air leak anywhere, orings are great shape. The only thing i can think of is this engine doesnt have much compression at all, it does have some but not much, would this cause flame out? my temps are about 190-210, its always been that cold from day one. if i can get ideas that would be great i can give any more detail that you want
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Old 04-30-2010, 04:31 PM
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I had an odd noise like a bearing going in a Picco once, I was told due to the wear in the engine it was piston slap. I would check to see if there is play in the piston to rod connection too maybe.
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Old 04-30-2010, 05:17 PM
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Doug, there are some excellent options for Nova help out at the track. (Billy, Casey, etc.) Or you could send it in to Fusion Motorsports and have them take a look. Just send mine in and heard back within a few days. Not good news for mine but they are always a ton of help.
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Old 04-30-2010, 06:01 PM
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My guess is that the rear bearing is in fact bad. I would make absolutely certain that it is good. The typical symptoms of a rear bearing going bad are the rattling noise and blown out glow plugs. If it is not addressed it WILL take out the engine(trust me, personal experience). Again, if you already checked the rear bearing, it could be something else, but I would check again one more time to be sure.
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Old 04-30-2010, 06:29 PM
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Originally Posted by losi_racer
Ok guys i have an issue

Last time i went out on my Nova +4 it sounded like the rear bearing was going, i was trying a 9901 pipe and i was told it makes it sound bad so i wasnt to worried, i ran all day, even a 30 min main no flame outs, but when i came home i wanted to make sure so i went back to 9853, the sound was still there, i also went 3 glow plugs within 30 min, figured the bearings went bad even tho i just changed them a gallon ago. I tore it apart today, looked at the bearings, o rings, and p/s. Bearings are great, o rings are great no tears, and the piston and sleeve have no scarring of any sorts. the internals actually look good for the amount of fuel that has on them.


I was wondering if anyone had any idea what could be the issue, i know its hard to do this online thats why im trying to get ideas. I dont think there is an air leak anywhere, orings are great shape. The only thing i can think of is this engine doesnt have much compression at all, it does have some but not much, would this cause flame out? my temps are about 190-210, its always been that cold from day one. if i can get ideas that would be great i can give any more detail that you want
Check the wrist pin slop in the piston douglas
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Old 04-30-2010, 07:06 PM
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Originally Posted by losi_racer
Ok guys i have an issue

Last time i went out on my Nova +4 it sounded like the rear bearing was going, i was trying a 9901 pipe and i was told it makes it sound bad so i wasnt to worried, i ran all day, even a 30 min main no flame outs, but when i came home i wanted to make sure so i went back to 9853, the sound was still there, i also went 3 glow plugs within 30 min, figured the bearings went bad even tho i just changed them a gallon ago. I tore it apart today, looked at the bearings, o rings, and p/s. Bearings are great, o rings are great no tears, and the piston and sleeve have no scarring of any sorts. the internals actually look good for the amount of fuel that has on them.


I was wondering if anyone had any idea what could be the issue, i know its hard to do this online thats why im trying to get ideas. I dont think there is an air leak anywhere, orings are great shape. The only thing i can think of is this engine doesnt have much compression at all, it does have some but not much, would this cause flame out? my temps are about 190-210, its always been that cold from day one. if i can get ideas that would be great i can give any more detail that you want
i would go with what monty said ..also i mean if it doesnt have compression it doesnt have compression ..thats never good in relationship to flaming out and motors running right ...if everything else looks good ..shoot alan an email ...his pinches are on time ...and he can also idle a few tanks back through it on the bench to get it ready ....on the wrist pin ...i have a 215k that has the exact problem monty is speaking of ..needs a new rod and pin and clips ....
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Old 04-30-2010, 07:58 PM
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Sooner or later the bottom of the wrist pin shoulder will blow out and kill the rest of the engine if the wrist pin is loose in the piston . Its like a jack hammer !!
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Old 04-30-2010, 08:06 PM
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Originally Posted by houston
Sooner or later the bottom of the wrist pin shoulder will blow out and kill the rest of the engine if the wrist pin is loose in the piston . Its like a jack hammer !!
exactley and the crank pin and rod bushing are like new money
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Old 05-01-2010, 04:01 AM
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i had a cracked head make the funny noise too. maybe slop in the rod?
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Old 05-01-2010, 10:29 AM
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Is there a way to 100 percent know if the bearing is good, I mean I'm turning it with my finger and it feels smooth
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Old 05-01-2010, 11:09 AM
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Originally Posted by losi_racer
Is there a way to 100 percent know if the bearing is good, I mean I'm turning it with my finger and it feels smooth
usually you feel it catch in the housing ...it will hit a spot and just hesitate ....also check one other thing related to the bearing make sure there are no small burrs on the inner bearing race and at the part of the crank shaft where the bearing rides ...i have also seen burrs on the crank cause the same problems ..but i mean yeh if it spins good no catches or hesitations ..you can usually tell right off the bat
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Old 05-01-2010, 01:33 PM
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Originally Posted by zixxer
usually you feel it catch in the housing ...it will hit a spot and just hesitate ....also check one other thing related to the bearing make sure there are no small burrs on the inner bearing race and at the part of the crank shaft where the bearing rides ...i have also seen burrs on the crank cause the same problems ..but i mean yeh if it spins good no catches or hesitations ..you can usually tell right off the bat
let me ask you this, this engine has had prob 10+ gallons on it, im not one to pinch, should i bother replacing the bearing again just to be safe and try getting it rolling or toss the p/s/r and keep the rest for parts for my other +4's. I do have a brand new ninja for my truggy so that +4 can go in my buggy
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Old 05-01-2010, 02:23 PM
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Originally Posted by losi_racer
let me ask you this, this engine has had prob 10+ gallons on it, im not one to pinch, should i bother replacing the bearing again just to be safe and try getting it rolling or toss the p/s/r and keep the rest for parts for my other +4's. I do have a brand new ninja for my truggy so that +4 can go in my buggy
if it has 10 gallons on it youve got your moneys worth ..theres no way with 10 gallons that it can have any compression ...you may not be one to pinch ..but 20 bucks can get you 3 gallons ..i mean thats a decision you have to make ..or just buy a p/s/r set and go again for half the price of a new motor ...the novas can handle a pinch for sure ..but 10 gallons is 10 gallons ....
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Old 05-01-2010, 04:05 PM
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Originally Posted by zixxer
if it has 10 gallons on it youve got your moneys worth ..theres no way with 10 gallons that it can have any compression ...you may not be one to pinch ..but 20 bucks can get you 3 gallons ..i mean thats a decision you have to make ..or just buy a p/s/r set and go again for half the price of a new motor ...the novas can handle a pinch for sure ..but 10 gallons is 10 gallons ....
you know what, pm me the speed shop address again, ill send it out monday and see what you guys think and ill have him pinch it
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Old 05-01-2010, 07:36 PM
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Originally Posted by losi_racer
you know what, pm me the speed shop address again, ill send it out monday and see what you guys think and ill have him pinch it
if there is any gray matter on your plug your piston is shot douglas

the wrist pin is probably loose in the piston and causing what i said bro , i do know what i am talking about when it comes to engines little buddy


is that on your plus 4 that has the really wierd low needle setting?
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