Nitro RC Starting Problem

[forpanos]

Hello guys.. a problem just popped up in my HPI NITRO RS4 RTR3 EVO.. when i put my rotostart (its old and little broken but does the job) i think the flywheel doesn't turn fast enough ,i can't even prime the engine (pass fuel from the tank to engine).. Instead of going to a hobby store to get it fixed, do you guys have any ideas what can i do ? Thank you in advance .. Sorry for my bad english i'm from Greece.. I may not explain the problem correctly so here is a video about it (listen for the engine's sound) https://www.youtube.com/watch?v=NKRp-nfw63o&feature=youtu.be

 

[Cornholio]

Without it being primed the engine will never start. Pull off the exhaust line and blow into it until fuel reaches the carb, then try starting it. From there we can troubleshoot your problem and get you up and running.

 

[forpanos]

i will try your suggestion ,but i think the piston doesn't have enough force to start the engine.. do you understand what i mean ? if i can't prime the engine by closing the exhaust ,how will the engine start ? the rotostart doesn't give enough speed to the piston

 

[Cornholio]

when i put my rotostart (its old and little broken but does the job)

I don't use rotostarts, but when you say "old and a little broken" , that sounds like a problem.

 

[forpanos]

it makes a whinning sound.. but it starts the car.. it might be the engine's problem .. anyway i will try your method later (it is quiet zone in my neibourhood) see if i can start it

 

[Greywolf74]

the rotostart looks to be spinning fast enough but if its not priming the engine when you hold a finger over the exhaust then you may have an airleak. also try to spin the flywheel with one finger. if you can spin it with one finger, especially if its very easy then you probably do have a compression issue.

 

[forpanos]

yes it is easy to turn.. so i have a compression issue

 

[ninnon]

yes it is easy to turn.. so i have a compression issue

You may have a compression issue, but first clean the thing ,and prime it manually

 

[hotrodrob]

How much fuel has been run through the engine?....sounds like you have a compression issue

 

[griff7373]

are you guys sure it's a compression issue?

 

[Greywolf74]

Nope. but I am sure that Rolex isnt wearing pants...

 

[ThunderTiger]

can we leave rolex and his (lack of) pants out of this please?

back on topic, is the glow plug tight and does it have the copper crush/seal washer under it?

Is the head bolted down tightly?

 

[forpanos]

yes everything is bolted tight.. the glow plug has the copper crush/seal washer under it and it is also tight.. the engine is old, since 2008 but 2010-2013 was not used

i tried starting it up by blowing fuel to the engine but it didnt start.. i think i might go to a hobby store because it seems to be something i may not be able to repair.. thanks for your answers

 

[hotrodrob]

Have you cleaned the carb really well?..if it's been sitting around that long there is no doubt that the fuel passages in the carb are gummed up

 

[ThunderTiger]

ok, dealing with the obvious..

After long storage, install new fuel lines, pressure line from exhaust to fuel tank and a new glow plug in the engine.

Dealing with the not so obvious..

Check the fuel tank cap is sealing properly and check the tank for cracks and or air leaks.

Strip the engine and seal with RTV.
Ensure engine head shim /gasket (if / where installed) is present and in place.

Check exhaust seal at engine end.
Check exhaust between header and pipe.

Use FRESH (as in new) fuel.

Ensure glow plug ignitor is fully charged.

Dealing with the engine compression, how many tanks have been run through it?

if you can spin the flywheel with ease and without feeling any "pinch" in the engine, you may be in need of a new piston and liner. Also a good opportunity to install a new connecting rod & wrist pin.

 

[ninnon]

yes everything is bolted tight.. the glow plug has the copper crush/seal washer under it and it is also tight.. the engine is old, since 2008 but 2010-2013 was not used

i tried starting it up by blowing fuel to the engine but it didnt start.. i think i might go to a hobby store because it seems to be something i may not be able to repair.. thanks for your answers

Thunder Tigers made a really good list above, I'd follow that. If it was me I'd replace the engine anyway if its been sitting around since 2008....

 

[ThunderTiger]

Ninnon, my 2.5 revo engine has sat idle since the last it ran.

Compression is still good, even after 6 years out of use. I am still going to run it as I know it's good.

 

[Rolex]

Drop some fuel directly into the carb and start it. If it starts and runs for a few seconds and then quits, you'll know the glow plug is good and you have enough compression for it to run. That would isolate the problem to the carb (most likely) or pressurized system.

 

[ninnon]

Ninnon, my 2.5 revo engine has sat idle since the last it ran.

Compression is still good, even after 6 years out of use. I am still going to run it as I know it's good.

This engine has had

Ninnon, my 2.5 revo engine has sat idle since the last it ran.

Compression is still good, even after 6 years out of use. I am still going to run it as I know it's good.

It wasn't the sitting around I was worried about, it was the 3 or 4 years of use it had had- if it was light use then it should be ok, but if it was heavy then it would probably be on its last legs.

 

[ThunderTiger]

True, but then, it rather depends how much fuel has been put through, whether the engine was cooked, whether it was left with the piston in the pinch zone.

Worst case scenario is the need for a new Piston and sleeve. A lot cheaper in some cases than a new mill.