jetting for stock SRX 80 with round slides

J

justinvintageyamy

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Joined
Dec 19, 2007
Messages
21
Age
52
Location
ne iowa
What would be a good start for jetting on a stock 1980 SRX with round slide Mikuni's put on it. I just bought the sled from Illinois that a gentleman had for sale on here. The sled was beautiful, and it was everything he said it was going to be. I tried finding the post again for pix, but couldn't. He put I believe 34mm roundslides on it, but I haven't miked them yet. (not sure how big of a diff. it would make if they turned out to be 38's??) I'll measure tonight. He got the settings and info from you guys on here for the new comet clutch etc..., but I don't know about the carbs. I'll read the plugs, but I would like a good starting point for the air screw, pilot jet, and main jet. Thanks guys!
 

OK. I did some other searches on here and found that a 79 is supposed to have 310's, 80 power jet, 30 pilot jet with a 36 mm. I thought mine was set up close, but found out that it had a 40 pilot jet and 300 mains. Sounds like I better go way up on the mains! Where should the other jets be? I just broke in the new cylinders and piston/rings tonight. I am planning on riding tomorrow to finish the break in. Any more info would help. Thanks. I was shocked to see the main jet screwed into the bottom of the bowl! I'm used to my newer sleds I guess. I couldn't read the other jet in the bowl. was that the power jet? Thanks again! I can't wait to ride my new vintage SRX!!!
 
DUDE, WHAT CARBS ARE THESE. YOUR ALL OVER THE PLACE HERE. THESE THE YAMAHA FACTORY POWER JET CARBS WITH THE DIAL ON THE BOTTOM. I ASSUME THESE ARE STANDARD 38 ROUND SLIDE CARBS. IF SO RUN 30 PILOTS, UP MAINS TO 350 AND RUN NEEDLE/ CLIP IN 3rd POSITION. THEY BASISLY CAN BE SET-UP LIKE STOCK 36, BUT THEY ARE SLIGHTLY LARGER WITH NO POWERJET. 3;16 (yammie tony)
 
OK, here we go. I went to take pictures and my battery is dead in the camera. It is a Mikuni 38mm roundslide, just like I used to run on my Cats. The difference is in the bowl. The main jet doesn't screw into the bottom of the body of the carb, it screws into the bottom of the bowl. Then there is like an air jet in the bottom of the carb that hooks to a hose that runs up to a fitting that is screwed into the bell of the carb. This has a small screw in air jet. I'm used to a cat mikuni carb. sorry for the confusion. I just don't want to have the jetting all off when I go for my first short ride. Thanks.
 
k, now i have the left cylinder full of gas....I think it drained there overnight. i had the sled on a run stand overnight, and now the damn thing won't start...full of gas in crankcase, mostly on left side.
 
ok....here we go. Got it running. hooked the old drill up to the clutch, unhooked the crank case hose that feeds the fuel pump, took the plugs out, and ran the drill in reverse with a towel over the spark plug holes for about 4 minutes. A lot of gas came out! After that, I hooked the carbs back up and it fired up. Here's my next dillema..sorry. It runs great on the Main jet (wide open), but it has the bwaaaah's. It really bogs from the engagement of 5k to about 7k. If your'e cruising at about 50mph and hit it, it flys, but if you are at 6k and punch it, it boggs terrible. I have a 40 pilot jet, and it calls for a 30. could this be my only prob? The clutching seems fine. Brand new comet primary, and new secondary spring and buttons. Purple prim. and n-1 weights. I tried dropping the needle all the way but it didn't help. air screws are at 3/4 turn. Please help?? Hopefully its just the pilot jets. Still don't know why my crankcase filled up overnight. I use a vise grip on the fuel line now until I get a fuel shut off. thanks everyone.
 
CRANK CASE PROBLEY FILLED UP BECAUSE YOU MIGHT OF HAD FLOAT STICK IN CARBS. OR YOU HAVE FUEL PUMP LEAKING DOWN. ANOTHER THING I HOPE YOU DON,T STORE THIS SLED AT NIGHT WITH BACK RASIED OFF THE GROUND. SO YOU HAVE A BOG UP TO 6000 ? YOU CAN TRY 30 PILOTS. 3:16 (yammie tony)
 
yeah, i was tired last night and forgot to lower the sled down in the back. I was just happy to finally hear it run. I will try 30 pilots tomorrow. What are the odds of a brand new fuel pump leaking down?? maybe better than I think, huh? float might have been stuck. I rode today and put a vice grips on the fuel feed line whenever I shut it off. I am going to put in a fuel shut off I guess.
 
sorry, forgot to mention that I tried dropping the needle to the lowest position and was unsuccessful. It helped a tiny bit though. thanks. I'll probably have to wait until Monday now to get a 30 pilot jet. I sure hope this is the problem. thanks.
 
sounds like you have power jet carbs like those used in a liquifire or invader. do yourself a favor and put as much distance between yourself and them as possible. they are a major pain to keep clean and maintain. check the kawi and john deere sites for more info.
 
Thanks everyone! Got it running great finally. I just need to figure out which way I'm going to go with the throttle 'throw' problem. It opens over 7/8's of the way. It'll work good for break-in. I really appreciate all your help.
 
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