still got starting problems

[soulfecker]

I made a long rambling post a couple of weeks ago, but will try again.
Gp200 indian stage 4 engine including std gears & sprockets. Casa megaphone exhaust. Scootopia 22mm carb 45 pilot, std atomiser, 123 main. Choke properly seated. Std air hose with scoop cut out. Used to start great on previous carb (30mm delly with foam filter) but then became troublesome when hot.
New rings fitted last year.
I've still got trouble starting after being run then left for 10 minutes or so. If I remove the airhose it starts then runs perfectly when the hose is replaced.

Any ideas? I'm thinking rebore or new cylinder & piston.

I'm not one to continually throw money at it just on a hunch

Paul

[Warkton Tornado No.1]

Another quick question is, there is a lot of talk about the height of the pickup, mainly referring to the newer BGM stators, but how do you measure it. is it from the top of the flywheel at the opening to the top of the pick up? if so, what should the measurement be(Indian flywheel)?

Paul

Did you ever resolve that likelihood or are you awaiting advice on how to do it?

As I type this, I realise I haven't thoroughly checked whether you said the air filter is/was in question. If you remove the element & refit the hose, is there still a problem?

[soulfecker]

I checked the height of the pickup. Looks okay. I haven't tried starting without the filter in the housing. Perhaps it may show something, but if there was a problem in that area, would it run so well once started. A dyno run did show Carburation being correct, although slightly rich at low revs (with a 50 pilot, hence running with a 45) it also did not run well, also tried a 48 pilot.

[Warkton Tornado No.1]

I asked about the pick-up positioning as ‘Scootering’ has just ran an article on it.

As for the air filter, I think it reasonable to assume that when removed there is less load on the starter motor (your leg!) allowing the engine to spin a bit quicker & further enabling it to ‘catch’ particularly if the filter is dirty/clogged or the ignition borderline on output.

When you tried the smaller pilots, did you adjust the mixture screw? It can make a big difference.

[soulfecker]

I thought the same about the ignition being borderline. I needed a new flywheel for another engine, so I bought one & fitted it, no difference. I did check the Lt coil resistance when the engine was hot & it was about 650 ohms. Although correct at about 525 ohms when cold(new bgm coil apparently a correct reading). I have another stator that I could try, just finished re-building it so it is unproven. I also fitted a new ducatti cdi. Anyone know if the high resistance reading is about right for a hot engine?

Paul