Carburettor problems XT600E - 3tb.

[carlhenrik_80]

As the search function at the site seems to be down i will write the question directly:
My XT600E -98 (3tb) runs well at idle, but when i throttle up to around 2000rpm it starts to backfire and doesnt rev any further up.

1st question:
Is the problem related to primary or secondary carb? Secondary throttle function seems to open well, maybe missing gas?

2nd question:
Pilot jet adjusts air mixture? At idle speed?? Setting? Tried 4 lapturns out.

Something to start with... :confused1:

/ Henrik

[svakak]

Originally Posted by carlhenrik_80

As the search function at the site seems to be down i will write the question directly:
My XT600E -98 (3tb) runs well at idle, but when i throttle up to around 2000rpm it starts to backfire and doesnt rev any further up.

1st question:
Is the problem related to primary or secondary carb? Secondary throttle function seems to open well, maybe missing gas?

2nd question:
Pilot jet adjusts air mixture? At idle speed?? Setting? Tried 4 lapturns out.

Something to start with... :confused1:

/ Henrik

I would check air filter, maybe remove it and check what happens. If engine works better without air filter, than either you have too rich mixture, or you air filter is too dirty. Try cleaning or replacing air filter first. If that does not help take carbs down and clean them. Check gas leven in carb.

If engine works even worse without air filter that would indicate that you have too lean mixture. Check two rubber parts that connect engine head and carbs, even little cracks could cause something like this. To properly check inlet rubbers you should take them down.

[Jens Eskildsen]

Start with Cleaning the carb and airfilter, and give it a new sparkplug.

And tell os more about the bike, has it sat for a while, did it just suddently start backfiring, or has it been faulty for youre entire ownership? Pretty important information.

F.x It doenst help to adjust the air/fuelscrew, if the carb is filthy and clogged up, or if theres no airflow trough the airfilter ect.

[carlhenrik_80]

The bike has been backfiring my whole ownership. But not this much! It was usable when i bought it..

I did change the intake rubbers to new ones and the rubber sealings as well.
Clean carb check! New air filter mounted.

It has a CRD slip-on mounted silencer, so i changed the jets from original 130/120 to 140/130 instead.

I even did regrind the valves i the top, because they where burned, and rubber valve-sealings leaked.
Also checked the valve clearence, seems to me its the first time thats ever been done, the bike has only gone 13000km.

Lot of work has been done, so far undone..

/ Henrik

[Jens Eskildsen]

Youre jetting is rich, you dont need to rejet mainjets for an exhaust-swap. If anything, go back to stock, and go up one number on the idlejet.

[carlhenrik_80]

Now I have tried three different carbs, with the same results as before.
It seems to me the problem isnt the carb at all.
Could be ignition problems. Already saw there is a weak spark..
Someone who had problem with the CDI-unit at a certain rpm??
More ideas where to look?

/ Henrik