Recently got a set of 99' M900 Mikunis for 30 buck on ebay, and the carbs are practically new. I was going to slip them on another bike, but my Paso's webers are....well, you all know.
Can the M900 carbs be used? If I switched out the jets for an M750 spec, is that the way to go? Also, I notice from previous discussions that the standard pull only Paso throttle will not work, and I need a push/pull. Its hard to find Monster throttles used, and I do have a friend selling some 999 and 916 vintage push/pull throttle cables/housings. I know they are fuel injected, but just glancing at them in my shop I didn't see anything that wouldn't work on a Paso Mikuni conversion without too much trouble, except for the bar ends.
Newer Monster Mikuni's on an 87 Paso
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Ducalisti
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motiztab
Hi Ducalisti
I am right in the midle of carrying out such a conversion!
From what I have been told the 750Supersport is closer to what is needed for the Paso. As I understand all Mikunis are the same but the jetting will be differant but you know that bit.
I have not checked this but the 900 inlets are to long you will need 750/600 inlets.
Regarding the push pull cable I have been looking at my carbs and think that a single cable will work, having said that I have ordered new cables for a Monster not be too bad a price at between £12 and £16.
The only trouble that I have encountered so far has been lack of clearance for the rear carb float bowl and the mounting bracket for the fuel pump.
What are you doing about an airbox?
I am right in the midle of carrying out such a conversion!
From what I have been told the 750Supersport is closer to what is needed for the Paso. As I understand all Mikunis are the same but the jetting will be differant but you know that bit.
I have not checked this but the 900 inlets are to long you will need 750/600 inlets.
Regarding the push pull cable I have been looking at my carbs and think that a single cable will work, having said that I have ordered new cables for a Monster not be too bad a price at between £12 and £16.
The only trouble that I have encountered so far has been lack of clearance for the rear carb float bowl and the mounting bracket for the fuel pump.
What are you doing about an airbox?
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Ducalisti
Hello motiztab,
I am starting to agree with you on the need for a push/pull style throttle. I really see no reason to use one, it seems as if the stock Paso pull style is good enough- the mikuni's have a strong return spring.
I am working on a little contraption to retain the stock choke mechanism as well. Right now I am using a mocked up aluminum bracket that can be easliy made with a pair of sheet metal shears (I will post pics and a how to when I am done). This piece will allow the choke mechanism (the sliding bar) to be used with the stock cable (with some added hardware.)
As for the air box, I haven't decided on what to do. The clearance is such that the 900 inlet runners (as you mentioned) are too long, so I fabricated a new set in my shop. This puts the Mikunis and a slightly sharper angle than the 750/600 runners and are not as long, giving me some added room. My plan is to put the tank in place, cover the carbs with some plastic wrap, and spray an insulation foam (here in the US it's available at any hardware store) and allow it to harden between the tank and the carb. Its a very brittle foam so once is dries I can remove the tank and the foam will take the shape of the area between the carbs and the tank. This will allow me to make a mold for an airbox to be made out of fiberglass or carbon fiber.
Hopefully I will have some pics soon and I will post the link to my website so everyone can see the process.
Cheers
I am starting to agree with you on the need for a push/pull style throttle. I really see no reason to use one, it seems as if the stock Paso pull style is good enough- the mikuni's have a strong return spring.
I am working on a little contraption to retain the stock choke mechanism as well. Right now I am using a mocked up aluminum bracket that can be easliy made with a pair of sheet metal shears (I will post pics and a how to when I am done). This piece will allow the choke mechanism (the sliding bar) to be used with the stock cable (with some added hardware.)
As for the air box, I haven't decided on what to do. The clearance is such that the 900 inlet runners (as you mentioned) are too long, so I fabricated a new set in my shop. This puts the Mikunis and a slightly sharper angle than the 750/600 runners and are not as long, giving me some added room. My plan is to put the tank in place, cover the carbs with some plastic wrap, and spray an insulation foam (here in the US it's available at any hardware store) and allow it to harden between the tank and the carb. Its a very brittle foam so once is dries I can remove the tank and the foam will take the shape of the area between the carbs and the tank. This will allow me to make a mold for an airbox to be made out of fiberglass or carbon fiber.
Hopefully I will have some pics soon and I will post the link to my website so everyone can see the process.
Cheers
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motiztab
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Ducalisti
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motiztab
Ducalisti
Ok I will give it a try.It worked for me.
Ok Left hand carb feed the rear cly?Yes. If so between the two carbs will be 2 "T" fuel pipe connectors, top one is the fuel "In" from the pump. Lower one vents to a fuel resistive container, more about that later. On the float bowls next to the drain screws you will find the overflow outlets, attach a small bore pipe to each and route to exit below the engine, mine are with the battery breather pipe under the swing arm.
At the top of each carb will be a right angle elbow, one will be exiting the rear carb (left) towards the front (right carb). The front carb elbow will exit in the direction of the frame. Both of these elbows exit to the right and also to the rear. These are vent tubes, pipes attached here should have the black plastic one way valves fitted, they are not to flow fuel but air so therefore the air flow will be resricted but thats what we want. Route these to exit in the same fuel resistive container used for the lower "T" connector.
Regarding this container if you look at a monster running these carbs on each side if the frame will be a black plastic triangle shape box what you need to do is make one of these, I used a model fuel tank for radio control planes, cost about about £3. Attach this to the side frame make 3 holes to take the vent pipes from the top of the carbs (elbow connectors) and the lower "T" connector.
Regarding the inlet manifolds mine have 2 thread holes each side of the inlet, thats 4 in total. I have blanked one on each off. Of the remaining holes one has the vacum take off for the Scottoiler and the other for vacum balancing of the carbs.
Regarding the fuel pump you will still need the "Y" joint connecter from the Webber set up. It needs to be connected as it was with the Webber, No change here. If you do not have this then there is a danger of the feul pressure bursting the seals on the carb.
I have not finished my set up yet but have been running the engine with this plumbing of the carbs.
I have not used the Oil Heaters built into the float bowls on my carbs as I would have to repipe all the oil runs the bore size is all wrong for us. Also I have not wired up the electric carb heaters that mine have, may well later but that will not effect mixture.
The above has worked for me and as said in a early posting the engine runs again. Trouble is my local dealer has still to come up with the monster throttle cable, and I have still to finish the air box.
How have you made your airbox? did you convert the old one or make a complete new unit? I have a clearance issue between the rear carb and the frame, just will not be much in the way of airflow here unless I go to K&N sytle.
just update my web page with a few images of the carbs
Ok I will give it a try.It worked for me.
Ok Left hand carb feed the rear cly?Yes. If so between the two carbs will be 2 "T" fuel pipe connectors, top one is the fuel "In" from the pump. Lower one vents to a fuel resistive container, more about that later. On the float bowls next to the drain screws you will find the overflow outlets, attach a small bore pipe to each and route to exit below the engine, mine are with the battery breather pipe under the swing arm.
At the top of each carb will be a right angle elbow, one will be exiting the rear carb (left) towards the front (right carb). The front carb elbow will exit in the direction of the frame. Both of these elbows exit to the right and also to the rear. These are vent tubes, pipes attached here should have the black plastic one way valves fitted, they are not to flow fuel but air so therefore the air flow will be resricted but thats what we want. Route these to exit in the same fuel resistive container used for the lower "T" connector.
Regarding this container if you look at a monster running these carbs on each side if the frame will be a black plastic triangle shape box what you need to do is make one of these, I used a model fuel tank for radio control planes, cost about about £3. Attach this to the side frame make 3 holes to take the vent pipes from the top of the carbs (elbow connectors) and the lower "T" connector.
Regarding the inlet manifolds mine have 2 thread holes each side of the inlet, thats 4 in total. I have blanked one on each off. Of the remaining holes one has the vacum take off for the Scottoiler and the other for vacum balancing of the carbs.
Regarding the fuel pump you will still need the "Y" joint connecter from the Webber set up. It needs to be connected as it was with the Webber, No change here. If you do not have this then there is a danger of the feul pressure bursting the seals on the carb.
I have not finished my set up yet but have been running the engine with this plumbing of the carbs.
I have not used the Oil Heaters built into the float bowls on my carbs as I would have to repipe all the oil runs the bore size is all wrong for us. Also I have not wired up the electric carb heaters that mine have, may well later but that will not effect mixture.
The above has worked for me and as said in a early posting the engine runs again. Trouble is my local dealer has still to come up with the monster throttle cable, and I have still to finish the air box.
How have you made your airbox? did you convert the old one or make a complete new unit? I have a clearance issue between the rear carb and the frame, just will not be much in the way of airflow here unless I go to K&N sytle.
just update my web page with a few images of the carbs