Spitting Mikunis

  • Thread starter Thread starter Terry Dymond
  • Start date Start date
Thanks for all the suggestions, I've wound themixture screws out a bit, they are now one turn from fully closed. I'll check the fuel flow from the tank but I'm pretty sure it's ok. Next step is to raise the needles a notch, as suggested.

Thanks fellas.
 
Aren't the mixture screws on the Mikunis ahead of the venturi? I would think unscrewing would lean the mix rather than richen. The Dellortos have the mix screw on the wet side [behind the venturi] and they do richen when opened.
 
Raised the needles on the Mikunis (couldn't believe how easy it was) and a test ride around the block (30 kms) indicated that the spitting problem was cured, Thanks for the tips.
Some more questions: I'm running a DMC2 ignition system on curve 2, is there a curve that is suited to the Mikunis and second; are the filter pods prone to problems in the rain?

Thanks in advance.
 
Terry Dymond said:
Raised the needles on the Mikunis (couldn't believe how easy it was) and a test ride around the block (30 kms) indicated that the spitting problem was cured, Thanks for the tips.
Some more questions: I'm running a DMC2 ignition system on curve 2, is there a curve that is suited to the Mikunis and second; are the filter pods prone to problems in the rain?

Thanks in advance.
Click to expand...

Terry,

An ignition curve is not intended to suit the carbs that are fitted, it is primarily dependant mainly on valve timing/compression ratio and fuel quality.  The carbs should be set up to suit the engine and ignition, not the other way round...

Curve 1 is closest to the stock setting, quite ok for most applications with stock engines, slightly aggressive ignition advance giving the most low-down poke.  With an otherwise stock engine and decent fuel quality, stay close to the stock advance of 32? and use a curve that suits your riding style.  If your engine is highly modded, you're on your own.  Any single mod may result in different ignition reqirements, sometimes a long and winding road...

piet

 
Why would raising the needle create a more rich mixture at idle. According to this diagram the needle only really kicks in at 1/4 throttle.

http://www.carbparts.com/mikuni/mikuni_tuning_info.htm

Are the RS miks different to this diagram?

Tks
Ed
 
There's a certain amount of overlap between idle jet/mixture screw, slide cutaway, needle jet and main jet. But I wouldn't expect raising the needle to help the idle problem much (if at all), and may make it too rich at middle throttle openings. However, it's a simple matter on Miks to adjust the needle, so why not give it a try and tell us what happens?

Have you checked for leaks in the manifolds?

Something else that I just thought of is that one of the idle mixture screws could have the tip broken off and jammed in the orifice. So that carb would be running quite lean at idle. Might pay to pull the mixture screws out and check the tips.

There might also be a bit of crap in the idle circuit of one of the carbys. I had a very similar thing on my Ducati the other day. One idle jets was blocked with  old gummy fuel crud. Lots of backfiring and poor running from idle to about half throttle.

 
Have checked manifolds will check again. Spraying aerostart or similar didnt make any difference.

Will check mixture screw tips although I have been very careful after being warned.

Cheers
ED.
 
Why are you worried about rain on the pods Terry are you forecasting a wet ride to a certain Laverda function later in the year?? I am riding in a wet suit this year "fuck off rain".
On another subject Terry could you PM me Ians contact details I have a mate that needs to see the seat mountings for a hinged tripleseat in the Adelaide area.
Thanks
 
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