justinvintageyamy
New member
I recently got back into sledding for my kids. I have owned Vipers, F7's, ZR's, ZRT's etc... in the past, and got out of it because of kids...now my kids are getting old enough to want to sled themselves. I just purchased a 1980 SS 440 and a 1980 Exciter 440. The SS i believe either has a secondary that has an extremely week spring, or the sled is starving for fuel on top end. I think that it is running short on fuel because of a blocked fuel tank filter or screen, but I'm not sure what there is inside these tanks? It runs great until you punch it wide open, it wants to slowly die, like the secondary is opening too far too fast, but it never seems to overcome it. I cleaned the carb and blew out all the jets etc, and put in an inline filter. Ok, the exciter runs better... it flies on top end, but has a low end bog. clutching seems really close. I adjusted the screw (air screw?) on the top of the carb out some more, and it seemed to help temporarily, but still wants to die at 1/4 throttle, but will idle. After I cleaned the 'greenish and full of tiny foreign particles' carb, it worked pretty good for about 5 minutes, but went back to its bog that eventually wakes up and when wide open it runs great. What is the adjustment supposed to be on the screw on the top of the carb? I tried 1 1/2 turns out like a round slide Mikuni, but no avail. They were both set at about 4 1.2 turns when I got them. I'm not familiar with the butterfly carbs. Oh, the SS440 has an aftermarket K&N type filter on it...not sure if I should jet up or not. Sorry for the LLOOONNNGGGG post, but the kids want to RIDE!!!! Thanks guys. Justin
Filter is on the end of the pickup hose in the tank. They are easy to change, you just have to take the seat and instrument panel off, and then pull the spring retainer on the cap where the hoses connect and pull the whole pickup assembly out of the tank.
The butterfly carbs have a fuel screw not an air screw. Screw out to make richer, and screw in to make leaner.
Stock setting for idle mixture screw is 1 5/8 turns for the EX440 and 1 1/2 for the SS440. This is if they both have the stock Keihin carbs on them. These are 2 different engines, and 2 different carbs on these.
Stock jetting was . . .
145 on the EX and 135 on the SS.
If it were me, I would pull both tanks and clean them out. Then put new urethane hoses on and clean the carbs again. I am guessing that debris is getting into the carbs or busting loose somewhere in the carbs itself. Replacement in-tank filters can be purchased at any of the mail order houses, but the inline ones (like visi-filters) allow an easier change in the future.
Keep us posted with what you find.
The butterfly carbs have a fuel screw not an air screw. Screw out to make richer, and screw in to make leaner.
Stock setting for idle mixture screw is 1 5/8 turns for the EX440 and 1 1/2 for the SS440. This is if they both have the stock Keihin carbs on them. These are 2 different engines, and 2 different carbs on these.
Stock jetting was . . .
145 on the EX and 135 on the SS.
If it were me, I would pull both tanks and clean them out. Then put new urethane hoses on and clean the carbs again. I am guessing that debris is getting into the carbs or busting loose somewhere in the carbs itself. Replacement in-tank filters can be purchased at any of the mail order houses, but the inline ones (like visi-filters) allow an easier change in the future.
Keep us posted with what you find.
justinvintageyamy
New member
if i put inline filters in both sleds, what do I do to the pick up tubes in the tanks? do I still need to have filters on the ends of them? thanks for all the answers so soon. So you are saying that the mixture screw is a fuel screw, not air screw. This is the one on the top of the carb on the intake side, correct? thanks. Should I be concerned about the reeds at this point? I will take the tanks off and clean both of them and replace the lines. thanks again.
BuckSwashler
New member
sounds like the pilot jet is clogged on the exciter, its really small and hard to get to but it controls fuel metering on the first 1/4 of the throttle. It could be the clutching on the ss or the belt wore too thin, but it sure sounds like the main jet to me, or the fuel pump not keeping up (blockage) or it could be the pick up
justinvintageyamy
New member
for whatever reason, i don't remember taking the pilot jet out of the carb on the exciter. I'll check that. I did run carb clean through all of it, and took out the main jet to make sure it wasn't blocked on both sleds. The ss has a new belt, but the clutching may be off. I do think it's the pick up though. I'll find out tomorrow night. Thanks for all the ideas guys. Any tips on the pick up? must use filter? I am definitely putting in inline sight filters on both.
BuckSwashler
New member
Seems like you dont need two filters. If you can't find anything interupting the fuel flow to the ss, i suppose its possible that the kn filter is letting in so much more air than the air box that it needs much higher jetting, but thats just a guess..., may want to check secondary clutches are all the way together and not froze up at all...
If you choose to eliminate the in-tank filter and use an inline one, you can pull the metal tube out of the old in-tank filter assembly and put it back on the hose for a pickup. I guess I am torn on the best filter choice. The in-tank ones work fine and rarely need replacing unless you allow a lot of debris into the tank. The filter surface area on the in-tank filter is a lot larger than any inline filter so should not clog nearly as soon. However if you do need to replace it, you have to pull a few parts off.
After thinking about this some more, I would simply replace the in-tank filter unless you are in the habit of putting dirty fuel into the tank.
After thinking about this some more, I would simply replace the in-tank filter unless you are in the habit of putting dirty fuel into the tank.
BuckSwashler
New member
Ding, you going to the mt brighton hill climb this year?
I'd like to, when is it?
BuckSwashler
New member
i have heard rumors, nothing official i am assuming after ski season tho. march... Did this guys fix his sleds yet?? the suspense is killing me, his kids suffering and all...
justinvintageyamy
New member
Got it fixed!!! thanks everyone. It was different symptoms, but similar issues. I replaced the in tank filters with weighted barbed hose ends, and used all new fuel line that ran to new inline viewable filters, before the pump. Now I'm on to my next project....my brand new 1980 SRX!! I have a current post on right now about jetting for this sled. It is a newly rebuilt, and just broke in last night. Now I need to know my jetting for this sled with 38mm roundslides. please let me know. Thanks again!!