VintageVmax.com

im new to the forum so need to be patient with me. i had bought an 83 540 vmax this year and in the process of restoring it. all fuel lines were rotted off and the shut off valves leaked. bypassed valves, and have oil pump disconnected. got it to run. will idle good. mid to full throttle just boggs down. just found out that the ports on the bottem of the bowls are to be connected to the ports on the side of the carb. runs alittle better but not rideable. found web site that shows 2 jets in the bottom of each bowl, as this machine had none. no idea if it needs them or even what size or if thats my problem. carbs are very clean also. any help would be greatly appreciated.

I can not see how the sled would even run without at least the M.J. ?

http://www.vintagevmax.com/1986_service.htm
Carburetor- Mfr.- Type/ Size/ Qty/ ID Number Mikuni- VM38/ 38mm/ 2/ L:80N-00 R:80N-00
Main Jet/ Main Air Jet 290/ 2.5
Slow Jet/ Slow Air Jet/ Air Screw �/ �/ �
Pilot Jet/ Pilot Screw (Turns Out) 40/ �
Needle Jet/ Jet Needle- Clip Position/ Cut Away/ Air Jet Q-0/ 6DH1-4/ 3.0/ �
Power Jet/ Power Air Jet L:135 R:130/ L:1.5 R:1.4
Fuel Inlet Valve/ Float Level 1.5/ 18.1mm
Idle Speed 1500 rpm

your probably going to have to post some pictures of your carbs so we can see if they are stock or off of something else

THERE SHOULD BE A POWER JET AND A MAIN JET IN THOSE BOWLS. 3:16 (yammie tony)

viewtopic.php?f=2&t=1529
http://www.yamaha-motor.com/partviewer/ ... _-_1983%29

tyler, please help me. i don,t know where pilots jet go. LMFAO. 3:16 (yammie tony)

actually i just re read your post tony... i thought you were trying to say that all of the jets went in the bowl...

what your are trying to tell the OP is:

Someone probably took the the jets out of your carbs and never put them back. You most likely need all of the jets, including the ones (power and main) that screw into the float bowl

both carbs had #310 jets in main carb body, and pilot jets size unknown. 2 empty holes in both bowls. pics not the best.

no tyler, i stated jets in bowl. SOMEBODY BLOCKED YOUR POWERJET OFF AND REMOVED BOTH MAIN JET AND POWER JET FROM BOWLS. THE MAIN JET IS THERE IN PICTURE 2. 3:16 (yammie tony)

where are all them jets you stated. if that jet in the bottom of carb is the main jet do i need any in the bowls ? and i dont see where there is anything blocked off.

YAMMIEGOD 3:16 wrote:no tyler, i stated jets in bowl. SOMEBODY BLOCKED YOUR POWERJET OFF AND REMOVED BOTH MAIN JET AND POWER JET FROM BOWLS. THE MAIN JET IS THERE IN PICTURE 2. 3:16 (yammie tony)

Tony is right, most Mikuni Round slides had the M.J. exactly where your's is located and did not use the P.J. setup so, you only have the 2 jets with the Pilot being the other and screwed up in the bottom of the carb body. The 310 M.J. is sized up from 290's with out the P.J. that would normally be adding fuel.

I'll bet your bog is a worn belt, wrong C. to C. distance, sacked out spring, worn weight/rollers/bushings in the primary, a secondary in need of cleaning, buttons or bushing. Inspect all then the mark the clutch sheeves with a line from a sharpie then take her out a give her a good run then check how much of the sharpie marks are cleaned off the sheeves and this will tell how well the clutches are working.

had the primary gone through by my local race shop. i no it needs a new belt. did not do the sharpy thing yet. fuel is mixed 25:1 was told to break it in then go leaner. could that be a problem.

25:1 is plenty rich in oil and I take it you disconected the oil pump if not you could be running lean.

all oil pump lines have been disconnect. just got new belt in yesterday gona give that a go.