popping - more tuning needed

[kevxs]

hey guys the bike is running pretty good but it is popping and backfiring during acceleration out the left pipe mostly when under 3000rpm.

this only happens for the first 10mins, once it is warmed up it hardley happens at all.

there is no popping during engine braking.

the plugs look a little rich.

any suggestions?

thanks!

[CatatonicBug]

Did you sync and colortune? Sounds like you need to adjust the fuel/air mixture screws a bit (aka colortune).

[kevxs]

naw i've only done a bench sync (last season). don't own a sync tool or colourtune. i wonder if these can be rented? haven't got much time to build the sync tool, renting one would be nice

[CatatonicBug]

I've never known of a place to rent a sync tool, but that doesn't mean you can't... However, if you own a bike, you should also own a sync tool of some kind. You can make one in an hour or so by following one of the many descriptions here on the forum. Colortune plugs are almost definitely non-rentable. You can tune by ear if you know what to listen for (there's a tech tip about it). However, a proper sync is essential, and should be done EVERY TIME the carbs are messed with. As far as I'm concerned, if you take the carbs off the bike for ANY reason (even if you do nothing to them), you should sync them again.

If you have the funds, the very best setup can be purchased from the UK via carbtune.com. Be sure to get the storage case for it too. This is also the same place to buy the Colortune plug.

[TomRodgers]

I kinda agree with C Bug.... jury not in about sync'n after doing nuthing to them, but its so easy to do with guages, why not...

I do hafta say the Carbtune setup is WAY nice....very compact, very light, and even with my hand bandaged up from surgery, i sync'd the carbs with no problem!!!!!

Definately worth the money. not that i have spent it yet....

In your area, use this forum, Facebook, or flyers at the store to see if anyone in your area has one. One of my co-workers had one and he let me borrow it.

[anarchy18]

Help with a synchronizing tool

I kinda agree with C Bug.... jury not in about sync'n after doing nuthing to them, but its so easy to do with guages, why not...

I do hafta say the Carbtune setup is WAY nice....very compact, very light, and even with my hand bandaged up from surgery, i sync'd the carbs with no problem!!!!!

Definately worth the money. not that i have spent it yet....

In your area, use this forum, Facebook, or flyers at the store to see if anyone in your area has one. One of my co-workers had one and he let me borrow it.

QUESTION: Bought this carbtune unit and when i hook it up im barely getting any kind of reading, gotta rev the motor high enough to wake the whole neigborhood to have the bars raise up. And 1 of em isnt coming up far enough to tell anything at all. How do you use this thing you got any tips? Thank You

[natemoen]

QUESTION: Bought this carbtune unit and when i hook it up im barely getting any kind of reading, gotta rev the motor high enough to wake the whole neigborhood to have the bars raise up. And 1 of em isnt coming up far enough to tell anything at all. How do you use this thing you got any tips? Thank You

Sometimes if you are running lean at idle you won't really be getting much vacuum. Opening the idle mix screws will usually result in the vacuum coming up. Also you want to have the idle as low as you can get it when using it.

That said, it only works really at idle because the vacuum goes down as the rpms go up.

[mack]

Ontario riders

There are a few guys in your area. PM tinman or Bullet and ask if you could swing by and use theirs. I'm about 1 1/4 hour from you. If you want to take a run down here, I'll do it with mine.

[CatatonicBug]

QUESTION: Bought this carbtune unit and when i hook it up im barely getting any kind of reading, gotta rev the motor high enough to wake the whole neigborhood to have the bars raise up. And 1 of em isnt coming up far enough to tell anything at all. How do you use this thing you got any tips? Thank You

You may have some major vacuum leaks. Make sure you have the restrictor valves in the hoses, about 4" from the carb boots. Keep idle at 800-1000rpm, or as low as you can while performing the sync. You'll find that the better the sync is, the lower you can turn the idle speed and still have it idle well. While idling, with all the hoses connected, try spraying some starting fluid around each carb boot to see if the RPM changes. If it does, that means there's a leak, allowing the starting fluid to get sucked into the engine. Solve that leak first.