SuzukiSavage.com - 38 mm Mikuni Roundslide help: won't idle

vroom1776

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Re: 38 mm Mikuni Roundslide help: won't idle
Reply #15 - 04/12/06 at 08:39:53

Hey, To anyone reading this thread besides Lancer and SR (he read it at least once!):

BTW I got a USED carb from Lancer, NOT a NEW one.

...don't want to scare off any one...

Lancer: Any suggestions until the new valve comes?

Also, I put in the 310 main... still too big... stumbles and cuts out at the top, btu I'm getting more of the top end back as I go to smaller jets. Will install a 300 main today...

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LANCER

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Re: 38 mm Mikuni Roundslide help: won't idle
Reply #16 - 04/12/06 at 09:58:52

I kind of stumped right now. Is there any possibility of an air leak around the carb anywhere? The needle, needle jet, main jet, & pilot jet are all new. I believe the gasket on the bowl was new too if I remember right ?? Check the rubber gasket on the carb top. It seemed that it was OK when I looked at it but I could have assumed too much with it. If those things are OK then we are back with the needle valve again.

According to the tuning chart the #310 main jet is what is called for at 4000' above sea level. but if you engine wants it leaner then make it leaner. If you need smaller jets than the #300 let me know, I have a #280 & #290 in the box.

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vroom1776

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Re: 38 mm Mikuni Roundslide help: won't idle
Reply #17 - 04/12/06 at 10:05:25

I will test for air leaks at the screw on cap, rubber flange, and air filter. The float bowl gasket seems in good shape/new.

I previously checked for an air leak at the rubber flange by spraying carb cleaner at the interface and listening for an rpm increase... nothing.

As far as the 310 goes, it may be related to the float problem somehow... just too darn much fuel... don't worry about the jets. I can get them easily and cheaply in town...

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Savage_Rob Serious Thumper Alliance Member Offline Mechanically Inclined Amateur Posts: 6972 Texas (Dallas area) Gender:	Re: 38 mm Mikuni Roundslide help: won't idle Reply #18 - 04/12/06 at 14:29:40 Hmmm, I'm gonna need to check mine also. I finally got the vacuum port put back on and it's pretty solid now. Prior to that, she wouldn't run unless I had her on PRI and I prefer the vacuum setup.
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vroom1776 Serious Thumper Offline Posts: 2110 Gender:	Re: 38 mm Mikuni Roundslide help: won't idle Reply #19 - 04/13/06 at 08:16:52 I put mine on prime. Seems to have "fixed" the problem...
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Savage_Rob Serious Thumper Alliance Member Offline Mechanically Inclined Amateur Posts: 6972 Texas (Dallas area) Gender:	Re: 38 mm Mikuni Roundslide help: won't idle Reply #20 - 04/13/06 at 10:24:52 I never find any gas dripping or any evidence that it has... just that I can get a very slight amount on my fingertip by tapping the ends of the vent tubes after a ride.
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vroom1776 Serious Thumper Offline Posts: 2110 Gender:	Re: 38 mm Mikuni Roundslide help: won't idle Reply #21 - 04/13/06 at 10:58:26 yep, me too (now). However, if I go outside right now, 4 hours after I got off it, there is gas at the bottom of the tubes...
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Savage_Rob

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Re: 38 mm Mikuni Roundslide help: won't idle
Reply #22 - 04/13/06 at 11:38:40

vroom1776 wrote on 12/31/69 at 16:00:04:

yep, me too (now). However, if I go outside right now, 4 hours after I got off it, there is gas at the bottom of the tubes...

Hopefully you turned the petc0ck off of PRI when you parked. If you left it on PRI, it stands a much greater chance of overflowing just sitting there.

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vroom1776 Serious Thumper Offline Posts: 2110 Gender:	Re: 38 mm Mikuni Roundslide help: won't idle Reply #23 - 04/13/06 at 12:58:37 Yeah, it's on "RUN." But there is still the leak-drip-leak-drip going on...
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LANCER Serious Thumper Alliance Member Offline Savage Beast Performance Parts Posts: 10606 Oklahoma Gender:	Re: 38 mm Mikuni Roundslide help: won't idle Reply #24 - 04/13/06 at 17:50:40 I get the leak-drip thing as well, but I think it is from the pet c o c k loosing its ability to seal properly, so I just turn it to the off position. I have noticed these last months that even then it still leaks a little...I am looking at replacing the whole thing now.
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orrin7 Ex Member	Re: 38 mm Mikuni Roundslide help: won't idle Reply #25 - 04/13/06 at 19:16:26 sounds like the petcock is both of you guys problem. but don't buy a new one the guy at the motorcylce shop told me last week , there is a rebuild kit for them
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vroom1776

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Re: 38 mm Mikuni Roundslide help: won't idle
Reply #26 - 04/19/06 at 09:48:40

From "Carbs": http://suzukisavage.com/cgi-bin/YaBB.pl?board=RubberSideDown;action=display;n...

Lancer wrote:

I just found some interesting info on float level and tuning and will get it posted here shortly. I think it may help your situation.

OK, the guideline I found suggests that if the engine is acting like it is too rich at full throttle, then lower the fuel level by 1mm in the bowl. Then test ride to see if you have improvement.

End

I just want to keep all the info in one place...

Allright, so, like I said, above, the float height is presently 17mm, the bottom end of spec. So I need to move it to 16mm, correct?

What do I need to bend? The float arm? leave the center tab alone?

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vroom1776 Serious Thumper Offline Posts: 2110 Gender:	Re: 38 mm Mikuni Roundslide help: won't idle Reply #27 - 04/20/06 at 12:23:48 bump significant changes...
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Tim Krantz Guest	Re: 38 mm Mikuni Roundslide help: won't idle Reply #28 - 04/21/06 at 09:57:13 Just wondering what air filter are you using on the Mikuni..... I was thinking of a sock type, or K&N. If K&N, does it have to have an angular tube-to air cleaner? What about the crancase breather??
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vroom1776

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Re: 38 mm Mikuni Roundslide help: won't idle
Reply #29 - 04/21/06 at 10:16:04

Yep, KN filter. I don't know the aprt # offhand as I got it from lancer. If you want to use a KN pod with the stock carb, it is RU-1250. Breather filter should be available at any HD place. Mine was made by drag specialties. I orginally put it here:

but I cut up the air box some more and stuffed it in there.

I think some folks are running the straight round KNs, but not real sure how they forced them in there. For me, removing the battery case and mangling the air box was the way to go.

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