T350 not firing fully on one side

[Chairman]

Hi Folks,

I have rebuilt a 1971 T350J with a crank rebuild, new seals and a rebore with oversize pistons. I have stripped the carbs right down and cleaned and air blown every orifice, fitted new points, condensers, plugs and suppressor caps. The timing has been checked by strobe and the carbs set up as per the manual but I still have the right hand cylinder not performing fully i.e. the heat in the cylinder head and the pipes is not as hot to touch by a long way. Hope this makes sense as I'm starting to wonder about my abilities.

Any advice pointers or help appreciated.

CM

[Alan H]

Make sure that the carbs are opening together and the same amounts.
It appears that they are slightly out of synch and especially the tickover is slightly more on one cylinder - check the amount the slides are 'up' at tickover.

[Alan H]

..........

[joethebike]

Extract your muffler baffles and check for a rag you may have left in there, yes it happened to me, and check the baffles to see if they are clogged with carbon.

[grumpy56]

I have this same problem with the left cylinder on my GT380 when starting it cold. Full engine including crank rebuild. Carburetor is OK as I tried a different one on that cylinder and the same issue exists. Removed exhaust and nothing blocking it. Electronic ignition. Plenty of compression. After I get the revs up on the middle and right cylinders, it kicks in and seems to then work fine. Even can let it set for an hour and will start up and run fine. I'm also at a loss as to why this happens. Also had a 1970 T350 in the past that did the same thing on one of the cylinders.

[jabcb]

For the GT380 with cold start problems:
The choke jet is in the bottom of the float bowl. Make sure it’s clear. Use a flashlight to confirm that it’s clear.
Make sure that the choke circuit passages are clear. Use a flashlight to confirm.

For the T350 not firing fully on one side:
Balance the carbs at full throttle by adjusting slides so that completely clear the the intake opening at the same time.
For the carb slide idle screw, raise the weak-side carb slide a bit. That should help.

Do some riding to clear out the motor from rebuild excess lube, and from not running ok.
Then rebalance the idle. Set it to idle ok one one cylinder (I do this for something like 2k rpm).
Then repeat for the other cylinder & adjust idle screw to get same rpm.
Then set the idle with both cylinders running by adjusting both idle screws the same amount.

You may have to repeat the adjustment after some miles, perhaps a hundred or two.

Had a cold cylinder on a GT380. Did this & now the exhaust headers are about the same temp when measured with a Harbor Freight infrared thermometer. Runs much better too.

[grumpy56]

Thank you jabcb!!!

[Chairman]

Hi Guys,

Thank's for the replies.

I removed the baffles and there are no obstructions but the baffles have been shortened and are now only 5" long??

Balanced the carbs as per advice and the slides are in unison at the top of the intake bore, the bike was idling quite well and there now seems to be slightly more heat in the right side now (by touch).

I'll take it for a run and see how it goes for now.

Cheers.