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Any advice please guys
Posted: Mon May 23, 2016 10:11 am
by John
I am at my wits end. If I cant get this sorted no renmark for me

A few weeks back on a normal run the 138 started missing and back firing really badly and loudly. To the point it was kangaroo hopping along the highway. I persisted and it seem to come right. I made it home, pulled the dissy cap off and the button inside the cap was gone. Couldn't find it anywhere. I put a new button in but she still had a miss while doing around 35 - 40 mph.
I decided to get the carby rebuilt by procarb. Put it back on and still had that miss. I cracked the shits and took it to a local fella that has had a bit to do with greys and he put a bigger jet in the carby (53) that seemed to improve it but it still has that slight miss and lacking power.
I pulled the dissy out and found the old button so took that out. Put the dissy back in but still not great. (It has the permatrix module so no points)
So it idles perfectly, under slight revs its missing but will rev hard without missing.
Has me stumped.
Anyone have any ideas???
Im thinking finding another dissy and dropping in ??
Re: Any advice please guys
Posted: Mon May 23, 2016 10:16 am
by Blacky
A replacement dizzy sounds like as good a place as any to start mate - maybe the advance spring or mechanism was damaged by the button bouncing around in there ?
Re: Any advice please guys
Posted: Mon May 23, 2016 12:25 pm
by John
Thanks Blacky. I still think its fuel so thought I might raise float level a bit first. If that's no better than yeah I think smart thing to do will be swap out dissy.
Bloody frustrating as all hell though. It should be easy to figure

Re: Any advice please guys
Posted: Mon May 23, 2016 8:02 pm
by fingers
John wrote:Thanks Blacky. I still think its fuel so thought I might raise float level a bit first. If that's no better than yeah I think smart thing to do will be swap out dissy.
Bloody frustrating as all hell though. It should be easy to figure

""...."..................................................
The float level should be set between 5/8 and 11/16 from top of fuel bowl down to fuel level .....there s a fine line between running and flood so stick to makers specs ......just saying mate ....
Re: Any advice please guys
Posted: Mon May 23, 2016 8:37 pm
by Craig Allardyce
John I run a 55 main jet as I had a slight miss whilst cruising but would go away once more pedal was applied (opening of power valve). It was running lean on the 51 jet.
Either way for your probs I would swap out the dissy with a known good one, same for the carby. Check manifold gaskets for leaks as well as vacuum pump for wipers and washers, and booster leaks. I am also wondering if your dissy shaft has too much endfloat. Does the cam have its clip holding it onto the breaker plate (under the felt washer).
Also look at checking fuel pump pressure and flow rate, water in fuel, and coil or condenser issue. Are you running a 4 ohm coil with the pertronix unit?
Re: Any advice please guys
Posted: Mon May 23, 2016 10:20 pm
by DanFranko
With regard to your carb I have one from Procarb too and it's been spot on. Had great dealings with them so try give them a call if you suspect any issue with the carb and I am sure they can help. Just a thought!
Re: Any advice please guys
Posted: Thu May 26, 2016 7:00 pm
by John
Re: Any advice please guys
Posted: Thu May 26, 2016 7:13 pm
by Craig Allardyce
How did it jump a tooth John? Just curious. Glad you've got it sorted for Renmark.

Re: Any advice please guys
Posted: Thu May 26, 2016 8:38 pm
by Trev
Great to hear John, see you at Renmark.
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Re: Any advice please guys
Posted: Fri May 27, 2016 8:03 am
by parisian62
1 tooth makes a big difference! Well done John. See you at Renmark

Re: Any advice please guys
Posted: Fri May 27, 2016 9:59 am
by Blacky
Re: Any advice please guys
Posted: Fri May 27, 2016 10:58 am
by Errol62
I would have assumed you checked and set timing advance by some method. Not sure how many teeth on the gear but would have to equate to 12 to 18 degrees on the dizzy so half that at crankshaft.
Anyway good outcome.
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Re: Any advice please guys
Posted: Fri May 27, 2016 11:52 am
by John
I should explain better. LOL
Timing was spot on according to the timing light, but the distributor was hard up against the side plate so I couldn't advance it at all.
Took the dissy out old screwdriver into the oil pump trick, turned around , dissy back in and now I can actually advance it enough to fix my issue.
That's what I meant to say.
Re: Any advice please guys
Posted: Fri May 27, 2016 12:14 pm
by Errol62
That makes sense. Now you can tune by ear. Advance till she pings under load them back off etc. good work.
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Re: Any advice please guys
Posted: Sat May 28, 2016 8:13 am
by Blacky