TwoRivers
Petty Officer 1st Class
- Joined
- Mar 10, 2010
- Messages
- 344
OK, here we go again with this 1987 Suzuki DT30. This is a two cylinder two stroke. It starts and runs great from mid to wot.
This thing will scream and run like a clock all day at just under WOT. (4700 - 4800 rpm)
It will idle OK (not great) at about 1100 rpm in neutral and about 1000 in gear.
Manual says it should idle in gear at 650 to 700 rpm.
I'm using a TinyTach and rpm jumps around sometimes as much as 100 rpm and engine shakes, coughs and sneezes (never sure which one it's doing) at 650 to 700 rpm then dies.
Timing is set dead on. I've adjusted the air fuel mix a gazillion times. I've cleaned the carb and replaced what parts are still available. I've de carbed the engine using a variety of methods.
Compression is 119 in each cylinder.
Plug ceramics are both medium to dark honey brown. Electrodes are not fouled.
Maybe it's fuel related? (carb, lines, tank, etc.) But there is always a trace of some fuel mixture around the bottom plug. It's just a few drops less than a half teaspoon and the cylinder head cover seems to be discolored from raw fuel?
Could I have a gasket leak that the compression test doesn't detect?
Anyways to check? I understand you can't do a leak down test on a two stroke? Is that correct?
Also, if I change the head gasket can I reuse the bolts? I have a Clymer manual and it doesn't mention changing the bolts.
Any help appreciated.
Hope you're all out on the water by now.
Rob
This thing will scream and run like a clock all day at just under WOT. (4700 - 4800 rpm)
It will idle OK (not great) at about 1100 rpm in neutral and about 1000 in gear.
Manual says it should idle in gear at 650 to 700 rpm.
I'm using a TinyTach and rpm jumps around sometimes as much as 100 rpm and engine shakes, coughs and sneezes (never sure which one it's doing) at 650 to 700 rpm then dies.
Timing is set dead on. I've adjusted the air fuel mix a gazillion times. I've cleaned the carb and replaced what parts are still available. I've de carbed the engine using a variety of methods.
Compression is 119 in each cylinder.
Plug ceramics are both medium to dark honey brown. Electrodes are not fouled.
Maybe it's fuel related? (carb, lines, tank, etc.) But there is always a trace of some fuel mixture around the bottom plug. It's just a few drops less than a half teaspoon and the cylinder head cover seems to be discolored from raw fuel?
Could I have a gasket leak that the compression test doesn't detect?
Anyways to check? I understand you can't do a leak down test on a two stroke? Is that correct?
Also, if I change the head gasket can I reuse the bolts? I have a Clymer manual and it doesn't mention changing the bolts.
Any help appreciated.
Hope you're all out on the water by now.
Rob