The parts list on novarossi site has them listed as 17011

http://www.novarossi.it/2012/images/...a/S21P5XLT.pdf

They list 17011 for the Roma, too and it's not supposed to have it either....

Vapour Lock
 

Dose anyone here know how to solve a vapour lock issue ?

I have a Plus4 BTT which is only just run in and am having problems with vapour lock where if the engine stopes or runs out of fuel and when you go to restart it there's just no way. It wont even fire at all. The fuel just gets to the carb nipple and shoots straight back.

Funny thing is its not like its too hot either. I put my Exergen temp gun on the carb and it was only showing 185 when it was doing it.

The next run i did ritchen up the top end a couple hours but its still no different with the vapour lock problem.

The engine runs fine out on the track. Great really. Its just if it ever stops for any reason your not gona get it started again for at least the next 15 minutes or more. :confused:

I've been having an issue with my p5. I've got about 1.25 gallons through it so far and break in has been fine. My issue is since I have started leaning the motor it flames at the end of the straight as soon as I let off the throttle. It generally happens if I adjust the idle to where it should be. I currently have the idle high just to avoid this problem. It runs fine in the infield and I'm getting runtimes right around nine minutes w/ the 8mm restrictor so I know the engine is not overly rich. Good pop off the corner and good smoke. It's been cold here, down in the 40's, when I've been at the track and the motor is running a little on the cool side ~200. I've tried going both ways on the hsn and the lsn and I get the same result. Should I start over with my needle settings? Could the motor still have enough mechanical pinch to be stalling when I drop the throttle? Thanks for any help.

what fuel and glowplugs do you run ?

Running Byron's 30/11 and nova #6

thats a solid combo, tho depending on your climate a hotter plug may help you some......

is your track conditions dusty ?

sweeet , I imagine the price will go up a bit but its a great move imo

judging by what merdith has shown and the exploded view which was updated on january 9 of this year , the p5xlt is now dialed!

Yes, track was dusty one of the days. New filters both days out. I may try a hotter plug, but the weather is looking to change for a little warmer here. I also ran new clutch bearings and made sure the clutch shoes were not dragging on the bell. I checked all gear meshes and the drive train is free also. It seems like it flames only after being full throttle with sustained rpm. If I let off slightly and then get back on throttle it doesn't occur.

185 degrees at the carb seems pretty hot. I've overheated the carb warming an engine with a heat gun and fuel would bouce back into fuel line as you described. I could hear the fuel sizzling as it tries to enter carb/carb throat. Still may want to check entire fuel system for leaks or blockage, and check exhaust gaskets also. May also have some gunk in fuel inlet banjo fitting on carb.

Yeah i did replace all fuel lines and re-routed them just to rule that side of things out.

Just checked the gaskets and found the one that joins the pipe to the pipe manifold was sliced open and had a little bit hanging off it. Was still mostly intact though. I think it must have got too hot and softened too much.

I have put another Novarossi carbi on to try that next. Never had it happen before on other Nova's so will try that next and see what happens.

sounds of a lean bottom to me.

I agree with repete. I had a similar issue at a track last summer that had a long straight into a sweeper. engine would cut out as I got on the throttle again exiting the sweeper. Thought it was the HSN and opened that up and the problem was still there. Fattened the bottom end 2 hours and it went away.

Hello everyone, just wanted to let everyone know we now have Power Plates for some of the Novarossi engines. Please check out the link, and if you have any questions please feel free to ask.

http://ebmods.wordpress.com/2013/02/18/part-pp-3/

Yep check and reset your idle gap and retune your LSN.