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cutting out after high revs
RobBrown - 30/8/13 at 07:21 PM

Hi All,

I've been struggling with timing on my Pinto or a number of years. So this week I finally got round to fitting the megajolt I had on the shelf.

It started straight away , albeit ran like a bag of spanners

At the same time I have been trying to fit bike carbs.

After a bit of tweaking I had the engine running reasonably smoothly at idle, but when I push to high revs (3000rpm+)settling back to idle then runs rough and cuts out. The engine has trouble starting again.

I'm not convinced the bike carbs are set up correctly, but everything was running relatively OK at one point, idling and revving to 2000 OK.

Any initial ideas of what to tackle first? Especially the cutting out after high revs.

Now struggling to start at all now, and I've not changed anything?

Thanks

BTW Megajolt running with TPS, 2.0 pinto, R1 carbs, Standard Cam.

Seems to hint at fuel starvation


RichardK - 31/8/13 at 02:57 AM

First off have the main jets in your carbs been drilled out to about 1.65? If not do that first, then look at ignition.

Cheers

Rich


RobBrown - 31/8/13 at 01:14 PM

Thanks Rich

I've previously ascertained that the main jet size is broadly correct, from my previous fumblings with the dizzy fitted.

From a bit of googling I think I may have a faulty coil.

I've removed and cleaned the plugs and have tested the coil. Will look to replace this to see whether this solves the issue.

I'll update this post once replaced and tested.


black fingernail - 31/8/13 at 05:47 PM

Is fuel filter ok?


Xtreme Kermit - 31/8/13 at 07:34 PM

Are the diaphragms ok on the carbs?


RobBrown - 1/9/13 at 12:14 PM

Diaphragm's look OK.

Fuel Filter a little grubby, could probably do with replacing. It's an in-line glass one, so will need to check whether the internals come out or whether I need an entire unit.

But I think ? it was to do with the main jet running rich, 9.1AFR when the revs pick up and essentially flooding the engine.

I leaned off the needle and the high revs now runs at 12.5-13 AFR.

Trouble is that it still really struggles starting so will focus on the idle jet and mixture screw to see whether this helps.

I'm more convinced now it's to do with the carb setup, rather than the just installed Megajolt, which seems to be OK.