scott_jangers
Active Member
Hi there,
Yesterday I got hold of a CL350 which had been given a half-arsed cafe makeover but was being sold as non-runner due to tuning issues. It has a pair of Mikuni VM28 round slide carbs which look very similar to those found on an two-stroke RD350. I was told it did run when the PO bought it, but it was pretty rough. He messed about with it changing main jets, etc, but had no joy.
The plan is to check the valve clearances and ignition timing and then see if I can get the engine to tick over, but the carbs will need some love before that happens.
I've opened up the carbs to find out what's in them and to put them through the ultra sonic cleaner and this is what I know....
Main jets 280
Pilot jets 30
Slide 2.0
Needle 5L1 (richest setting)
So I understand that none of this is stock (apart from the slide maybe?) so someone's fiddled about with it. The main jets seem way out. I'll inevitably reduce the main jets to around the 160-180 mark, but first I am focusing on getting the engine to idle. The biggest question I have is regarding the air jet, as it appears to be intentionally blocked. A stock VM28 should have man air jet size of 0.5. I'm uncertain as to why this blocked and can only assume that is due to it being used on a two-stroke. I'm wondering if I can drop the pilot, needle size, etc to compensate, or drill the blockage out and tap for a 4mm threaded air jet?
Any advice would be great as I would like to at least attempt to get these carbs working before I fork out my hard cash on a set of 'pre-jetted' VM30's.
Many thanks!
Yesterday I got hold of a CL350 which had been given a half-arsed cafe makeover but was being sold as non-runner due to tuning issues. It has a pair of Mikuni VM28 round slide carbs which look very similar to those found on an two-stroke RD350. I was told it did run when the PO bought it, but it was pretty rough. He messed about with it changing main jets, etc, but had no joy.
The plan is to check the valve clearances and ignition timing and then see if I can get the engine to tick over, but the carbs will need some love before that happens.
I've opened up the carbs to find out what's in them and to put them through the ultra sonic cleaner and this is what I know....
Main jets 280
Pilot jets 30
Slide 2.0
Needle 5L1 (richest setting)
So I understand that none of this is stock (apart from the slide maybe?) so someone's fiddled about with it. The main jets seem way out. I'll inevitably reduce the main jets to around the 160-180 mark, but first I am focusing on getting the engine to idle. The biggest question I have is regarding the air jet, as it appears to be intentionally blocked. A stock VM28 should have man air jet size of 0.5. I'm uncertain as to why this blocked and can only assume that is due to it being used on a two-stroke. I'm wondering if I can drop the pilot, needle size, etc to compensate, or drill the blockage out and tap for a 4mm threaded air jet?
Any advice would be great as I would like to at least attempt to get these carbs working before I fork out my hard cash on a set of 'pre-jetted' VM30's.
Many thanks!