oily back plate and roto start slipping helppp

[pritchard-13]

Every time i take my nitro cars out i have problems getting to the point now were I'm thinking of just selling up! Realy enjoy this hobby when they work! Here are some photos i clean all the oil and it fires up great but after a while it starts slipping to the point it wont grip atall I'm woundering if its the back plate?

---------- Post added at 7:20 PM ---------- Previous post was at 7:17 PM ----------

I am also running 25% as recamended by the model shop I've read up a few threads of the rotostarts being the problem will i be better of just fitting a pull start? One less thing to carry and charge aswell

 

[hotrodrob]

How old is the engine?

 

[pritchard-13]

I'm not sure it was on the truck wen i brought it 2nd hand it has good compression i took the back plate off to see what was going on now i can't get the pin in the piston to catch the shaft that the owb goes on

How old is the engine?

---------- Post added at 8:46 PM ---------- Previous post was at 8:44 PM ----------

The engine looks old in the photo because the amount of oil and dirt on it.. belive it or not the engine looked mint befor i took it out today as you can see theres a problem with the amount of oil

 

[hotrodrob]

If I were to guess I would say that the bushing in the backplate is bad

 

[pritchard-13]

Whats that the rubber o ring?

How old is the engine?

If I were to guess I would say that the bushing in the backplate is bad

 

[hotrodrob]

That shaft that the owb is on rides inside of a bushing, either that or your exaust gasket is seriously leaking bad, possible combination of both

 

[srusinek]

Clean the motor and starting housing the best you can and then apply some rtv sealant to the back plate just to be safe. My 5.9 had the same problem with high oil content fuels. Traxxas 20%, forget about it. Bryons rtr 20%, forget about it. Byrons race 2000 20%, all day no slipping. You just might want to see what your oil content is before you have to go through this all over again.

 

[pritchard-13]

I do no the bit the owb goes on u can push and tug and it will move very very slightly

That shaft that the owb is on rides inside of a bushing, either that or your exaust gasket is seriously leaking bad, possible combination of both

 

[hotrodrob]

It wiggles up and down/left, right slightly?

 

[pritchard-13]

How can i see what oil ect all i no is its 25% model technics

Clean the motor and starting housing the best you can and then apply some rtv sealant to the back plate just to be safe. My 5.9 had the same problem with high oil content fuels. Traxxas 20%, forget about it. Bryons rtr 20%, forget about it. Byrons race 2000 20%, all day no slipping. You just might want to see what your oil content is before you have to go through this all over again.

---------- Post added at 10:20 PM ---------- Previous post was at 10:18 PM ----------

Yea exactly that i just checked and does what you said

It wiggles up and down/left, right slightly?

 

[hotrodrob]

I've never used that fuel, usually it says on the container, otherwise just google it,...and incase your wondering you can pick up that whole backplate assembly for like 15$

 

[pritchard-13]

Does that include the bit that the owb goes on? I've searched them on ebay (uk) and theres none on there mines a 4.1 engine

It wiggles up and down/left, right slightly?

I've never used that fuel, usually it says on the container, otherwise just google it,...and incase your wondering you can pick up that whole backplate assembly for like 15$

 

[hotrodrob]

Ah crap, idk if there the same or not but for the 5.9 its all included, hopefully one of the diehard hpi guys will chime in,...btw how long does it take before the owb gets soaked

 

[pritchard-13]

Found one on the hpi site for my engine its all included but has been discontinued lol erm when i clean it all out itll start slipping after starting the truck about 2-3 times then after about 5-7 times itll slip to the point were it wont turn engine atall btw my car cuts out a LOT still trying to set it all up as the guy i got it from had set the needles back to factory

 

[hotrodrob]

Cuts out or bogs down? How much blue smoke do you have when this happens

 

[pritchard-13]

It will only start if i apply quiet a bit of throttle and have to keep tapping throttle while the trucks sitting there or it will cut out it dosent bog realy just the performance seems poor theres quiet a lot of smoke especialy when taking off full throttle.. some times cuts out when i apply throttle too.. id love to learn how to get these things running good as there good fun just changes the mood when they dont run proply lol

Cuts out or bogs down? How much blue smoke do you have when this happens

 

[nitrojedi]

If I were to guess I would say that the bushing in the backplate is bad

I agree with you on this 100%....this is a huge weakness with OWB equipped nitro engines....Only one company (Novarossi ) has made any serious effort to seal the shaft passing thru the backplate

end result is a engine that has a serious vacuum leak

 

[pritchard-13]

When on grass kinda leaves a small cloud of smoke behind there aint loads at full throttle but to me still seems more then should be at full throttle

 

[hotrodrob]

Sounds like a verry rich issue you have which also is playing a role in excessive oil, "cutting out" is a term we use for a lean issue

 

[pritchard-13]

Could this be a good answer to my truck running realy poor and btw i forgot to.mention i can twist my carb a bit aswell since removing the nut is as tight as it will go too

I agree with you on this 100%....this is a huge weakness with OWB equipped nitro engines....Only one company (Novarossi ) has made any serious effort to seal the shaft passing thru the backplate

end result is a engine that has a serious vacuum leak

---------- Post added at 10:49 PM ---------- Previous post was at 10:46 PM ----------

I'm confused because if theres a lot of blue smoke wich meens rich and cutting out meens lean i falt u can only be one of the other lol sorry if i sound thick here

Sounds like a verry rich issue you have which also is playing a role in excessive oil, "cutting out" is a term we use for a lean issue

---------- Post added at 10:50 PM ---------- Previous post was at 10:49 PM ----------

I do the spit test and the spit dont even evaporate ither it drys up but takes a long time my temp gun shows around 60-70 degree if that