Mikuni on an R80 help

[One Less Harley]

Not sure if a color tune will fit in plugs, but using one of those will let you see the spark and then you can tune by color of the spark, a bunsen blue is just about right, orange is to rich.

[Les_Garten]

Originally Posted by One Less Harley

Not sure if a color tune will fit in plugs, but using one of those will let you see the spark and then you can tune by color of the spark, a bunsen blue is just about right, orange is to rich.

Isn't it dangerous getting your head down there while you're driving down the road?

[Les_Garten]

Originally Posted by Stagehand

ok, I get it... I have heard the roller units were more expensive than the non's.. I also havent heard how to tell them apart, or which model numbers differentiated them. Any help there?

I was wondering about this as well last night.

I have HS40's on mine, as well as some RS40's.

The difference is the addition of an R, for instance:

So an HS with rollers is an HSR

A TM with Rollers is a TMR

You would most likely be interested in TMR's. The HSR's start at 42mm, they're Hawg Carburettors

[Stagehand]

TMR.. Arr arrr good to know, thank you. I heard hearsay they were easily twice as expensive (like 800USD/pair) but didnt rub themselves raw, and wear out the body.

[Les_Garten]

Originally Posted by Stagehand

TMR.. Arr arrr good to know, thank you. I heard hearsay they were easily twice as expensive (like 800USD/pair) but didnt rub themselves raw, and wear out the body.

Rubbing themselves raw... Don't tease me!

Not to mention, at least for the HS's, that the freakin throttle springs are monsters to hold.

[Airhead Wrangler]

Originally Posted by Les_Garten

..at least for the HS's, that the freakin throttle springs are monsters to hold.

Same for the VMs I'm using. I only managed to hook up one of them so far and it's already equal to the pull effort of both bings. The addition of the second carb could prove too much. It could also have to do with the Venhill throttle grip I'm using though.

[Les_Garten]

Originally Posted by Airhead Wrangler

Same for the VMs I'm using. I only managed to hook up one of them so far and it's already equal to the pull effort of both bings. The addition of the second carb could prove too much. It could also have to do with the Venhill throttle grip I'm using though.

I don't know much about VM's, but the HS's and RS's have 3 positions for the throttle spring. They come set for the heaviest spring position. Moving them to the lightest position helps a ton. Let us know if the VM's are like that as well. Hopefully this will give your right hand a little break, won't be no Sunny day at the beach though.

[Airhead Wrangler]

Originally Posted by Les_Garten

Moving them to the lightest position helps a ton. Let us know if the VM's are like that as well.

VMs don't have that option. Only one place for the spring to go: inside.

[Les_Garten]

Originally Posted by Airhead Wrangler

VMs don't have that option. Only one place for the spring to go: inside.

That's too bad, I feel your pain.

[RGregor]

Originally Posted by Airhead Wrangler

Same for the VMs I'm using. I only managed to hook up one of them so far and it's already equal to the pull effort of both bings. The addition of the second carb could prove too much. It could also have to do with the Venhill throttle grip I'm using though.

For Dellortos three different springs are available. Any chance that Mikuni has softer springs available?
If you give me the dimensions of your springs I could check with the Dello springs.

[Kai Ju]

Originally Posted by Airhead Wrangler

Same for the VMs I'm using. I only managed to hook up one of them so far and it's already equal to the pull effort of both bings. The addition of the second carb could prove too much. It could also have to do with the Venhill throttle grip I'm using though.

I don't understand why you have a hard throttle pull.
My VM 38s are a lot easier to pull than the Bings. Mind you, I did make my own throttle cam, or I should say that I modified the stock /7 cam to allow the throttle to fully open.
What kind of throttle are you using ?

[Airhead Wrangler]

Originally Posted by RGregor

Any chance that Mikuni has softer springs available?
If you give me the dimensions of your springs I could check with the Dello springs.

That's entirely possible. I haven't checked yet. I appreciate the offer, but I can't measure them at the moment because they're with my bike up in Seattle. I'm down in Mexico. Sorry.

[Les_Garten]

Sorry to participate in derailing the thread. Just one more throttle spring post.

I went to these guys a few minutes ago and they'll make me some custom springs for my Mikunis.

http://www.springsfast.com/custom.php

p.s. I will put some input into the OP though.

Not sure why you are so resistant to the AFR gauge. I had a colortune at some point and found it pretty useless for tuning, other than maybe idle mix.

You could find one(Innovate AFR) for a good price used on Fleaby. Use it to "PERFECTLY" tune your bike and sell for probably what you have in it and use it for practically free.

Innovate is the one you want.

They have a tail pipe sniffer, which may work on your bike. I would weld a SS bung in my headers, but the sniffer may work for you depending on the exhaust you have. Then you would have the Best HP and the Best Gas mileage. You wouldn't leave anything on the table.

I would think with those 32's, you would have killer stump pulling torque and awesome mpg if done right.

[Uncle Pollo]

Originally Posted by Les_Garten

That's too bad, I feel your pain.

Mine are soft.

[Airhead Wrangler]

Originally Posted by Uncle Pollo

Mine are soft.

Hmm. Maybe I hooked up the throttle using the 'fast action' side of the cam rather than the normal side. I'll have to check it again.

EDIT: I checked the specs and the thottle takes up 36mm of cable in either 68 or 80 degrees of rotation depending on which setting you use. I'm not sure how that compares to the stock BMW throttle though.