Board index Flathead Power-Technical Questions, Answers, and Suggestions Big Twin Flatties Tuning a Linkert carby help please

Tuning a Linkert carby help please

Moderators: Curt!, Pa

Post Sun Mar 01, 2009 5:33 am

Posts: 27
Location: Australia
I have just stripped down the M-58 carb on my U-model and for good reason after what I discovered in the bowl (the crud explained the crappy running). Now I have it starting easily and idleing reasonably well, but when I am running it runs with enough surge to make it do that horrible thing where the engine seems to be fighting with the drive system at low speeds (little surges if you know what I mean), as well as a type of RPM over-run when clutching to change gears, or at idle. It seems to take a while for the revs to settle down to an idle. Could this be an air leak in a gasket or flange, or another problem. I had the idle needle at about 5 turns and the high needle at about 2 turns which is about what the manuals recommend (plus the usual minor tweaking for a decent idle).

Does anyone have any ideas why I cannot get the thing to run a little smoother?

Post Mon Mar 02, 2009 9:43 am

Posts: 3117
Location: Central Illinois, USA
Strewth!

There is a strong possiblility that you have things amiss elsewhere than (just) the carb.

I strongly encourage you to investigate the integrity of the manifold assembly:
http://virtualindian.org/11techleaktest.html

A big rubber stopper works as well as a testplate, and is the only way to test each nipple into each cylinder separately.

Eliminate all leaks absolutely, and carburetors become quite friendly!

....Cotten
Last edited by Cotten on Fri Mar 06, 2009 6:24 am, edited 1 time in total.

Post Mon Mar 02, 2009 3:59 pm

Posts: 27
Location: Australia
Thanks Cotten. It looks like I will pull down the entire inlet manifold system and give it a thorough going over, I know that these old engines should run pretty sweet once set up properly.

Post Mon Mar 02, 2009 7:16 pm

Posts: 3117
Location: Central Illinois, USA
Strewth!

Please test the assembly before you loosen the manifold from the cylinders.

If it doesn't leak,... don't fix it!

....Cotten

Post Mon Mar 02, 2009 8:14 pm

Posts: 27
Location: Australia
No worries Cotten. I had a look and the nuts have had the usual butcher treatment over the years. I am actually looking at getting the motor done up this year and was also going to replace all those induction parts at the same time. Now just to get the time and gear together for the little jig.


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