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Jets for Stock Carbs

PostPosted: Fri Sep 26, 2014 8:16 am
by Kcfirebolt
Hi all,

Finally got the bike on the dyno last night. My air fuel values are running rich (11.5 vs. 13 target). The carb which only runs a big main jet (I don't know what else to call it) has a 165 jet. I haven't torn into the primary carb (the one with the idle jet) to determine jet sizes yet.

Does anyone know who made the stock carbs? Does anyone know where replacement jets might be found. Looking for a 155 for the main jet only carb. Need to lean out a step or two if I can.

Any suggestions?

Thanks,

Charles

Re: Jets for Stock Carbs

PostPosted: Fri Sep 26, 2014 8:59 am
by basser23
What bike are we talking about?
Tekai carbs on Skorp and baggy?
Yamaha dealers shud have jets ...keihin jets work too

Re: Jets for Stock Carbs

PostPosted: Fri Sep 26, 2014 9:36 am
by Kcfirebolt
Ahhh, yes. I imagine that info would be helpful.

1996 Skorpion Cup race bike. Stock carbs. TDM 850 box.

Re: Jets for Stock Carbs

PostPosted: Fri Sep 26, 2014 9:47 am
by Kcfirebolt
Found this. It might be helpful. Will pull the carbs tonight and see if I can match them up.

http://www.jetsrus.com/FAQs/FAQ_identify_that_jet.htm

Re: Jets for Stock Carbs

PostPosted: Fri Sep 26, 2014 10:31 am
by billr
basser23 wrote:Yamaha dealers shud have jets ...keihin jets work too

I bought a pilot jet from the Yamaha dealer.

Just don't tell the counter guy it's for an MZ... :?
Lie and tell 'em it's for an XT something or other... :twisted:
Don't ask me how I know... :D ...
Bill R

Re: Jets for Stock Carbs

PostPosted: Fri Sep 26, 2014 11:31 am
by DAVID THOMPSON
carb parts
cleveland ohio

Re: Jets for Stock Carbs

PostPosted: Fri Sep 26, 2014 12:00 pm
by Kcfirebolt
Thanks Dave. I just called them. They didn't have the ability to look up the bike and said they wouldn't know where to start.

Appreciate the idea.

Re: Jets for Stock Carbs

PostPosted: Sat Sep 27, 2014 6:55 am
by Kcfirebolt
So, who made the crabs? Mikuni? Tekei ?

Re: Jets for Stock Carbs

PostPosted: Sat Sep 27, 2014 9:03 am
by basser23
Tekei, but Kehein mains work I am told
My Skorp is a 96 also and has been rejetted for Cup, so I don't know whats in there ...yeah runs a litte rich on the street...

Re: Jets for Stock Carbs

PostPosted: Sat Sep 27, 2014 7:18 pm
by edfmaniac
You can find main jets for both carbs at Jetsrus. Just measure yours and compare them to the pics and specs listed on their site.

Re: Jets for Stock Carbs

PostPosted: Mon Oct 06, 2014 10:47 am
by zippy49
That's where I got mains, but they did not have the correct slow jet. Had to clean out an old one.

Re: Jets for Stock Carbs

PostPosted: Mon Oct 06, 2014 1:11 pm
by edfmaniac
The Mikuni VM28/486 #40 pilot jet works. It doesn't look like the stock jet but it functions just fine and is available at almost any place that carries Mikuni jets.

Re: Jets for Stock Carbs

PostPosted: Tue Oct 07, 2014 11:19 am
by zippy49
Hi KC, what sort of air filter setup are you using? I'm running 130/165 with no airbox and big K&Ns. Haven't dyno'ed it, but it seems okay. It's loaned to a relative, will ask him about fuel consumption.

Re: Jets for Stock Carbs

PostPosted: Tue Oct 07, 2014 5:19 pm
by edfmaniac
My carbs ran best at 130/155 and put out 59.5hp at the wheel. But my engine has quite a bit of work done to it.

On a side note, anyone who has even basic skills with a rotary tool and a sense for airflow should buy the Moose racing carb spacer and use it as template to match the carb boots to the intake ports on the head. I bet the average bike will gain a couple of hp here. Just be careful not to get a bunch of filings in your engine. I stuff the ports with paper towels and then put a plug of grease over the towels to make a barrier that will stop anything from getting past.