This is my set up No need for the very first alum plate That is there for a Porting job on intake! But a Standard Mikuni flange 38 mm I believe The Carb came off a 06 DR 650 from Ebay I believe it is a 40mm CV Pumper Throttle cable is OEM The choke is a std snowmobile carb choke with the flip lever Jetting is real rich at 147.5 main And 50 Piolt. THE one thing I found is the air filter (stock) needs to be mounted with the motor Not the body! There is a piece of angle iron ( bed frame) and a piece of flat down to motor mount And YES that is a 2" copper to PVC plumbing fitting ( I am a Plumber) And Yes that alt came off a Datsun, just removed the fan blade, it's like 60 amp
Nice! Glad to see more work around for the crappy old carbs! Thnx for sharing it. Is this a readily available carb? Decent price?
Yes many variations and it IS a Mikuni Not China crap! This is probably too large for most applications I also have a 33mm same from another bike or quad I will have to take a thin cut off wheel to it to get the OEM throttle cable to work My jetting is too rich and have not had time to get the jets out She screams though!
OK Just went out and measured the carbs! OEM is 30mm bore! Exhaust was like the same! I am running a full 2" straight exhaust with my hand made collector! But please forgive me, I am a snowmobile wrench! I forgot these are all CV carbs Constant Velocity Hmmm Is it Possible I am Not getting enough Vacuum To open the vacuum slide?
Nice. Not sure what that Yamaha carb was mm wise. Thought when we all were deep in this that we said a 32mm was perfect?
LOL Long story but I now have a dd 51t front and rear drive line In my 91 DB51t! I made adapter plates for the cross member to bolt up to And made another for the nose of the front diff. First one side and now the other front half shaft pop out! Not sure if my Death Wobble did it or was it? I have a steering damper now so fingers crossed.
ok so did you take the little round wire ring out of the cup? thats all that holds those in, its pops in/out pretty easy. if you really yank on one of those shafts you can pop it right out. so maybe your angle & twist were just perfect & let it pop out?
My clip was broke And found another piece of clip in dif! Ordered the choke mount for the Polaris carb!
Have you played with jetting anymore? Obviously lots of variables but I’m curious what jetting people are arriving at.
Yes I dropped the Pilot down and I will have to go back Rough starting and dies even with choke on. I have the 33mm choke ordered so my next step will be the smaller carb! But I am rebuilding (second time) my front end Then I will be able to get a true reading on jetting And top speed!
Gotcha, I have my 40mm starting and running really well but I agree a smaller carb would be better for the engine size. The bsr33 mikuni is what I had looked at.
Yes I have one as well Mine is off of a Polaris Sportsman 500 The issue with the carb above is it is NOT a CV carb and will lack vacuum
You said you ported your intake, how did you go about it? I just ordered a DR650 carb to test this out since I ran into issues with the HS40 I was using losing vacuum when the throttle was open. I am hopeful that a CV carb is the way to fix this.
Yes I have said that before I did not remove the intake, but did the exhaust. I radiused the intake and knife edged the center If I would have had it off I would have opened up the center cylinder even more On the exhaust is where most was done I have a long tube manifold and made a 3 into 1 collector and I have a full 2" exhaust. So you know the stock carb was a 32mm, the DR is a 40mm I also have a 33mm CV off of a 500 Sportsman The smaller may give more throttle response? My truck is Heavy, 2300 is what it weighs and about 60mph is about all it will do Once I get a chance I am going to try the 33! Jetting, increase the pilot to at least a 45 or 50 The main will depend on you air flow
i actually put a muffler back on mine recently.... made no difference in power or performance that i can tell. now its just pretty quiet. (used a new muffler for a 1.1L geo metro.)
OK here it is, this in my Professional Opinion The 33mm off of a Polaris 500 ATV is THE BEST carb for our trucks! The only modification I did was to take a 1/16 cut off wheel and make the slot for the throttle cable! The stock carb flange will work too (or the Mikuni aftermarket) I now have GREAT throttle response and accelerates even faster. So far top speed is about the same 60mph But that is fast enough
^^^^^ nice info! got a link to availability for the guys still doing carb models that come to this thread?
I don't have a link The biggist advice I can give is Get the OEM Mikuni flange And mount the air filter to the motor NOT the Body!
One other thing that was way back There is a vac port on the manifold and another at the carb flange! One goes to the advance on Dist Others goes up front to the 4 wd There may be a vac line from air filter to the Gas tank Carbon filet The air filter also has a 5/8" hose from the PCV on valve cover Stock throttle cable! Choke is the issue I had and I listed the Polaris adapter above I used a single snowmobile universal cable I had on the shelf It gives half and full choke positions and stays til you shut it off! I have jetting for it as well fairly close, may up the Pilot jet for winter ??
Jetting for the 33mm carb 147.5 main 35 Pilot May be a bit rich during the summer I'll keep this updated! So far I've had no issue getting to 65! By my speedo 80k is 55MPH on GPS
