88 js550 bogging

[john zigler]

John I won't get into a pissing match here with you ( or maybe I will, the day is still young ) but I personally have found over the years that it is always best to jet from rich to lean , way less chance of motor damage that way especially if you are a novice , if you are on here asking questions about jetting then it's a pretty good bet you are a novice and to me (It's always better to foul a plug than buy a jug ) as us oldtimers say.

My jetting advice leaves room for a margin of error , yours does not , I will say this barring complications like leaking crankshaft seals , some other air leak or a cooling system issue if he melts a top end using my specs I will buy him a new top end , I hereby challenge you on open forum to match my offer and remember one important thing here I haven't sold this guy anything nor am I trying to.

Terry, read my 1st sentence in my reply. Sorry, but I am far too busy here to get into a pissing match..... lol

 

[john zigler]

It was running good before we got the upgraded carb. We just decided to switch carbs because we heard the Sbn was a good upgrade to have. And yes it was a genuine Mikuni carb bought brand new.

You could try a 110, 115, and maybe a 120... main jet then. I still think this is way rich on a stock 550.

Again, what is your high speed screw set at currently? Have you tried turning it out? As Terry says above we like to keep it between 3/4 and 1-1/4. FOr tuning purposes you can bring it out as much as 2 turns. If it keeps running better as you bring the screw out, This indicates you need to go up on the main jet.

You really should be using a tach to tune the high speed circuit.

 

[WFO Speedracer]

Terry, read my 1st sentence in my reply. Sorry, but I am far too busy here to get into a pissing match..... lol

Yes John the first sentence is the one I have the problem with , a 105 main jet is not a good starting point PERIOD ,I think you could turn the high speed screw out three turns with a 105 in it and it still won't matter , if you don't want to admit you are wrong , fine , I can accept that, in fact I expected it , glad I wasn't disappointed , you have a great day now you hear !

 

[Jaxson]

Well it’s been awhile and we took it to a mechanic who said my top end needed rebuilt with 130 compression in one side and 90 in the other piston. We also found a tiny exhaust leak that needs fixed aswell. Hopefully after the rebuild it should be running good.

 

[Ryan Declark]

Well it’s been awhile and we took it to a mechanic who said my top end needed rebuilt with 130 compression in one side and 90 in the other piston. We also found a tiny exhaust leak that needs fixed aswell. Hopefully after the rebuild it should be running good.

Goodluck!