Seeking Mikuni TM Smoothbore Expertise

[Wheelman-111]

Greetings:

This carb looked like it had an oil port in the Treatland and eBay listings:

http://www.treatland.tv/mikuni-24mm-TM- ... -slide.htm
http://cgi.ebay.com/ebaymotors/Mikuni-T ... 06.c0.m245
It turns out all three of those PINK hoses are vents.


My pump is still connected. I can put the oil output into the single-port CT manifold by means of a T-fitting. I would prefer to have the oil atomized a bit better by delivering it to a spot near the high-velocity venturi, but dare not block any of those vents, which I presume hava a reason for being. I took the front off the carb but it's not clear how those vents are routed internally. The bowl vent goes to a standpipe as shown. I don't think any should be blocked by incoming oil. Suggestions welcome.




Now

[scooterwerx]

i believe you will have to run it in the manifold, a ruckus im working on right now has the same carb, its on a zuma motor though, and there is definitely no provision for an oil injection port. makes sense seeing as its a race carb and all, hes got his oil going into the manifold. easy enough to drill and tap a hole for 1/8npt or whatever you want to use...

[Wheelman-111]

Greetings:

Thanks Werx! A second manifold port is a good idea. However it's not as easy to find those 1/8" hose barbs as I thought. The ones I did find have this horrifically big threaded section - like 3/8"! If I could find one I could JB Weld carefully in there I would, but no-go. Jon (ZR50Blank) says he might have one but hasn't named his source yet.

I just figured the vac port to the petcock could stand a trickle of oil plugged into a T-fitting, unless someone has a better idea. I likes me oil pump.

[Bear45-70]

Making one is a no brainer. Get whatever size thread plug you want to use. Then find brass tubing and drill a hole in the plug to match the OD of the tubing. Solder the two together and you have what you want. I fortunately have a couple of boxes of small barbed hose fitting for my outboard mechanic days.

[SpyderMike]

from what i hear his soldering skill is worse than his painting skill

[Bear45-70]

from what i hear his soldering skill is worse than his painting skill

Well, my soldering skills are excellent but give me a paint brush or a spray can an you are lookin' to be in the same boat as wheelieboy.

[scooterwerx]

ahhhh the nice thing about living in southern california, in a few minutes i can drive to a place that has everything you could ever need to build anything. i can get 1/8npt to 3/16 barb, even 1/16npt to whatever size you want! drilling and tapping is super easy to, home depot has 1/8npt taps, i did have to go to the specialty tool place for the 1/16npt tap.

[Wheelman-111]

Greetings:

I did manage to cobble up a cable for the CV carb. Now I must do another for the Mikuni. Along with the hose barb in 1/8, I could use a soldering primer, Bear. Need anything from Timmy?

[scooterwerx]

#1 rule of soldering-----make sure its clean! and use flux, it really helps. i have several barbs in 1/8npt size, if yall cant get one in TX

[808BMW]

I don't know how the stock oiler works, but I can imagine it doesn't atomize well (if at all) dribbling down your manifold. If you don't run any premix, and rely only on the stock oiler, then your banking every piece of your bike on that oil somehow mixing in nicely on the way down.
Everyone I've heard using their oil pumps without adding a little premix has always had a "modded" oil pump. Since nobody seems to share their secrets I do not know what this entails, but I would be scared to run a stock oiling system, much less try to devise my own.
Also didn't you mention in the other thread that the adjustment screws are on the wrong side? That is a huge problem if your ever trying to tune anything. It's always nice to be different, but judging by the price on ebay this carb is more money for more headaches. If the main idea was to keep the oil pump and you can't do that, what else is there?

I'd just run a keihin/oko and premix my gas. Tried and true, I'd hate to blow that nice Nicasil bore.

[Bear45-70]

I don't know how the stock oiler works, but I can imagine it doesn't atomize well (if at all) dribbling down your manifold. If you don't run any premix, and rely only on the stock oiler, then your banking every piece of your bike on that oil somehow mixing in nicely on the way down.
Everyone I've heard using their oil pumps without adding a little premix has always had a "modded" oil pump. Since nobody seems to share their secrets I do not know what this entails, but I would be scared to run a stock oiling system, much less try to devise my own.
Also didn't you mention in the other thread that the adjustment screws are on the wrong side? That is a huge problem if your ever trying to tune anything. It's always nice to be different, but judging by the price on ebay this carb is more money for more headaches. If the main idea was to keep the oil pump and you can't do that, what else is there?

I'd just run a keihin/oko and premix my gas. Tried and true, I'd hate to blow that nice Nicasil bore.

All these wise words in the face of millions of oil injected scooters running everyday around the world and not blowing up. Gee, I wonder who is right, 808 or millions of scooters?

[808BMW]

I'm talking about modified motors. Most people I know still running an oil injector add an ounce or 2 to the gas.

That's also for oil injected carbs. I'm just expressing my concern that a barb added into the manifold won't atomize into the gas very well. I'd hate to see Wheelman blow up his brand new parts.


Yes, millions of stock bikes run on oil injectors, forever. Show me millions of modified bikes that are anywhere near as reliable.

[Wheelman-111]

Greetings:

Thanks for all the useful remarks.

I run 60:1 premix.

The pump trickles into a high-speed solvent flow dragging it along toward the engine. Does the oil need to be atomized? I dunno.
The Aero mani design received the oil there.

Second mani barb would be great. Oh and a step-by-step soldering primer.

[Bear45-70]

I'm talking about modified motors. Most people I know still running an oil injector add an ounce or 2 to the gas.

That's also for oil injected carbs. I'm just expressing my concern that a barb added into the manifold won't atomize into the gas very well. I'd hate to see Wheelman blow up his brand new parts.


Yes, millions of stock bikes run on oil injectors, forever. Show me millions of modified bikes that are anywhere near as reliable.

If the oil atomizes or not (usually never as it is to dense a liquid to atomize), it gets thrown out of the mixture along the way or the oil won't lube the bearings and rings, so it doesn't need to atomize like the gas does to function properly. Your theory has major holes in it.

What you seem to be missing is that when you add oil in the tank for premix you lean the motor out as there is now less gas by volume than there was with straight gas, thus requiring and re-jetting. So some unknowing individual sees your missive and premixes his stocker and blows it up because he leaned it out following you incomplete advise that doesn't apply to him.

If you mean modded motors you need to say that, but I disagree with your theory anyway, it depends more on how you run the engine that what mods are done to it.

[Wheelman-111]

Greetings:

I have jetted and tuned 3 bore kits to the premix and the pump formula. No worries there.

I agree the pump may not supply enough oil for a 50% displacement increase, hence the 2 oz./gallon added to the tank.

Considering the contents of the crankcases I have opened, oil in vapor form doesn't stay that way for long.

The throttle stop is on the left. The idle mixture is angled 45 degrees upward on the right and fairly accessible. It is good to be different, (I'm the CV guy, remember?) and I've always liked Mikunis.