Question regarding compression
 

First of all I'd like to say hello to everyone, as I am new here, and would like to thank everyone for all the usefull info that's already been provided to so many. Now for my question. I am not new to nitro, nor would I call myself and expert, I have never worked with a .46ci nitro engine before and was wondering about the amount of compression. The reason I ask is because I recently purchased a used GST and can't get it started (rotostart). I am able to turn the flywheel over by hand. Is that normal or is it time for rebuild? I also have fuel burnt onto manifold, does that affect starting? Lemme know what u guys think.

RE: Question regarding compression
 

Check a couple of things. The backplate one way bearing could be slipping, this means that the roto start will spin, but the crankshaft will not, also check the batteries in your roto start, it might not be spinning fast enough to start the engine. Check theese things first;)When you use the roto-start is the flywheel spinning? Is fuel reaching the carb when you try to start it?

RE: Question regarding compression
 

Also, yes, burnt fuel showing on the manifold IS a problem, in all likelyhood you need to replace the exhaust gasket.

RE: Question regarding compression
 

Soilwork is correct about the oneway slipping and checking the flywheel to see if its spinning when you use the rotostart or turning it over by hand. Now if you do find that the flywheel is spinning then I would take the engine out of the truck and replace the piston and sleeve. You can get a set w the connecting rod, from eBay for between $25-$50. I will post the link later when I get home...

Good Luck....

RE: Question regarding compression
 

Thanks for the reply guys. Here's the details:
- Rotostart batteries fully charged
- Rotostart does spin the fliywheel
- Fuel is getting to carb because when trying to start I can smell the burnt fuel (Sweet smellin' nitro)

I will try to start with a drill to see if I can get it started. I will order a new gasket and piston/sleeve/rod. Will let you all know when I get an update.

RE: Question regarding compression
 

Did you try resetting the needles back to factory settings?

RE: Question regarding compression
 

Sorry NitroAddict, I forgot to post the link to eBay listings, [link=http://search.ebay.com/search/search.dll?from=R40&_trksid=m37&satitle=CEN+Piston +sleeve&category0=]Here is the link to several sets with the con rods included[/link]


Dont forget that you will have to break in the engine as if it were new, since it mostly is new.. You can find the factory settings on [link=http://www.cenracing.com/downloads/Engine%20Doc%20NX76.doc]CEN's Download site found here!!![/link] You will have to set the factory settings just a bit richer for break-in you will want to be you get plenty of oil on the engine during break-in, but not so rich it wont start.. If you need help with the replacement and retuning for break-in let us know..

RE: Question regarding compression
 

Hello again,

My problem was the cooling head. The bolts were loose, which lowered compression. I got that beast started today :D I can't get over the amount of torque. Very happy with product.