OzVMX Forum

Clubroom => Tech Talk => Topic started by: Stewy138 on December 19, 2010, 10:56:20 pm

Title: Carby problem, I think...
Post by: Stewy138 on December 19, 2010, 10:56:20 pm
I have a PE175C which I recently changed the carby from 32mm to 34mm.  The other change at the same time was fitting an inner rotor ignition with an RM125A CDI.

Anyway, when I ride the old gal hard (no I'm not talking about my personal life, I'm referring to the PE now) then back off the throttle, eg on a downhill section, the engine starts to die (like its running out of fuel).  If I give it a good handful of throttle it recovers ok but will start to die away again if I start to back off.  Only does this when the engine is hot and doesnt seem to happen when I'm not riding as hard, and the engine presumably is a bit cooler.

Its not over-revving when it dies, so I dont think its running lean.  The plug is sooty and slightly oily after a ride.

Any thoughts  ????
Thanks,
Stewy.
Title: Re: Carby problem, I think...
Post by: vandy010 on December 19, 2010, 11:13:03 pm
what size pilot jet Stewy?
Title: Re: Carby problem, I think...
Post by: Stewy138 on December 22, 2010, 02:40:33 pm
Hey Vandy,

Yes i was thinking along those lines...the new card was apparently from an RM125M and the jets were all way different to the ones in the 32mm PE carb.  So I changed out all the jets from the 32 PE carb into the 34mm body.  Then went to a significantly bigger main jet (260, original was 190).  Logic tells me that the pilot would need to be larger too.

Will extract it and have a look...

Title: Re: Carby problem, I think...
Post by: Lozza on December 22, 2010, 05:57:41 pm
Do a proper plug chop and post a pic of the plug.Alternatively kill the engine while the problem exists.
Title: Re: Carby problem, I think...
Post by: oldyzman on December 22, 2010, 06:23:11 pm
Is there any possibility the choke is faulty and not turning off properly..
Brett
Title: Re: Carby problem, I think...
Post by: oldfart on December 22, 2010, 06:32:30 pm
check to see is float level is correct height.
Title: Re: Carby problem, I think...
Post by: Davey Crocket on December 22, 2010, 07:09:51 pm
Make sure your misses hasnt burnt the muffins ;D