hey guys, looking for a few answers about my 96 f3, i bought it about 6 months ago and have riden it almost every day, put 5k on this summer and am starting to run into an issue, could just be me getting used to the bike but i think im losing some power, i cant get the front wheel up at all, im not much for clutching but shouldnt i be able to raise it in first? i wasnt about to wheelie a bike i just bought and had no experience with but i gave it a go today and nothing happened, 7.5-8k on the tach, dumped the gas and immediately back on and nothing happened, boot full of acceleration but thats it, and im -1 in the front, also was riding today and came to a stoplight off an exit on the highway and coming down from higher rpm to a stop just kills the bike, it restarts fine but dies almost everytime, also takes a twist of the throttle while cranking to start if its already warm, if it sits 3-4 hours then a push of the starter instantly starts it with no gas or choke but hot it wont. also getting some backfires while rolling off the gas, i love the sound but not sure its normal. bike has exhaust and K&N filter (i know) and 30k on the clock. anyone have any suggestions? is this power normal? i have a buddy with a 400hp sti that i can barely pull away from, seems wrong. thanks in advance

 

Your bike sounds like someone add a free flowing intake and exhaust, but didn't do any jetting work. When you say exhaust, you mean a slip on or a complete system? Sounds like your bike is running lean. You could open the pilot jet screws a 1/4 turn each from where you are now and see if the popping and stalling gets better. If it does get better, you may need to go bigger on the main jets and/or raise the needles with shims.

 

I think it may be a full exhaust, not really sure honestly, the header has melted through part of my fairing so I doubt it sitting in the stock position which I would guess it has been replaced, header is a 4-2-1 and looks stainless, sound stock? I'll look into turning the screws tomorrow, if it's running lean would it smell like gas? Is that normal to smell to some extent? Also if it is running lean and I adjust the screw how will I know when it's correct? If it's lean an I make it more lean on accident what will happen?

 

possibility of burned valves

 

Usually gas smell from your exhaust would mean it is running rich. If the gas smell is around even when it is not running, it could mean a number of issues. Burnt valves usually make the bike run roughly. You said you had to open the throttle to start it when warmed up. Old VWs have that problem due to heat soak. Stainless exhaust would indicate a replacement exhaust, but you said it was quiet as a stocker.

I re-read your post and my initial running lean statement is not holding up. Your bike starts cold with no choke, dies after running at a stop, needs open throttle to start when warm. The popping on decel could be an exhaust leak due to the headers not being seated properly. There is a gasket that goes in the exhaust port that lots of people don't replace after removing the pipes.

So, could it be that the ram air bypass system that works at low throttle openings might not be operating properly, or, your pilot jets are out of wack, or, your carbs need synching. Easy, isn't it. The pilot jet screw is under the carb on the float bowl. It has a D shape screw in it, you need a tube of the right diameter and flatted on one side to fit the screw. I would screw one in til it bottoms lightly while counting the number of turns. VERY important to get the number of turns right. DO NOT overtighten the screw when it bottoms out. You should have 1 1/2 to 2 turns out as your setting. This is the easiest thing to check on the bike, after you take off the side fairings. All of the screws should be close in their settings.

 

Thank you for the info, I'll try and adjust the screws tonight and report back, oh and the bike certainly isn't quiet, it's very loud, and I I ride hard for 15-20 minutes then normal again it becomes less responsive and begins to backfire periodically at any rpm range

 

Got a brand name on the exhaust system?

 

Yea it's an mvr..? I've never heard of it before, guess it stands for mike velasco racing, anyone ever heard of it?

 

Velasco worked with Pops Yoshimura, Honda, and Erion Racing in the 70s and 80s. He is hooked up with D&D pipes now. I would wager that the system you have is full race system. If you don't have a jet kit in it, I would suggest you get one. Or, you can go up one or two sizes on the stock mains, and shim the needles with teeny washers you can get at Radio Shack. One or two washers maybe. Either way, you will have to fiddle with settings and pull the carbs, or have someone do it for you on a dyno. Jet kits usually have a ballpark setting in their instructions.

 

Interesting so is this a decent setup? I know yoshi and d&d are held in high regard. I'll just try an jet it, could already be and just not tuned properly, I'll have to pull it all apart, I know there are tutorials out there so I'm not asking for instructions but is this an afternoon job? Time wise? My local mc shop wanted $150 to clean/tune/sync which didn't sound bad until they said that was per carb, I'm more of a DIY guy as long as I can handle it