1993 Suzuki DT4

[robert53a]

Hi I just swapped out my power head on my little DT4 using the old magneto cdi and carburetor. Everything cleaned and reassembled. The carb set to 1 and 1/2 turns on the idle screw. The motor has good spark and compression( 90psi) but will only sputter. not sure what I did wrong but would like some advice on which way to proceed. Any advice would be greatly appreciated. Thanks.....Robert

 

[robert graham]

Double check fuel flow, pump, filters, carb float needle valve, etc....

 

[robert53a]

Thanks I'll check those, but it has gas to the carb. It's raining cats and dogs here in Seattle, first sun break it will go back in the tank for another try.

 

[Mohawkmtrs]

"gas to the carb" does not mean gas through the carb...re-check your carburetor work.

 

[robert53a]

-+I'll pull it and check it again and hope I find whats wrong. Thanks

 

[99yam40]

why did you adjust the screw to 1 1/2 turns out?
I have no idea if that Dt 4 specs call for that or not, but you need to be sure the service manual calls for what you set it at

 

[raczekp1]

when you do the powerhead swapa , did you swap all parts, electrical and FLYWHEEL.

flywheel can have key notch in different place, so timing is different

 

[robert53a]

Hi I used my old electrical componets and put the old fly wheel. I used 93 componets on an 1989 power head and din't think that would be a problem. It does sputter but also want to back fire. Ut oh will have to check it out. Thanks for the heads up raczekp

 

[robert53a]

I set the low speed idle at 1 and 1/2 according to the manual. The fly wheel p/n is the same for a 1990 and a 1993 DT4 and took it for granted it wouldn't be a problem. Was I wrong to think it would work? Let me know may be flywheel and crank are individually matched?

 

[99yam40]

Is it the same for the 89 power head you used

 

[robert53a]

It was a 1990 power head. my bad thinking it was 89. I'll pull the fly wheel again and have a look just to make sure key and grove are aligned.. I also went through the carb again and pulled all jets and tubes out and re-cleaned. cant fing much to mess up on the little thing. I appreciated evreyones thoughts and ideas....Robert

 

[99yam40]

Put a timing light on it to see where it is sparking at

 

[robert53a]

Hi not real familiar with timing light on a small two stroke. I see the pointer and reference marks on the wheel, but doesn't the motor have to be running to track timing? let me know if there is a static way to check. thanks

 

[robert53a]

as far as static timing I removed the spark plug and inserted a drill rod and gently rotated the fly wheel until the piston was at top dead center. the pointer lined up with the 0 mark on the fly wheel. Since spark advance is controlled by the CDI unit the fly wheel is correctly grooved to the crank. Is this right or wrong thinking. Thanks...Robert

 

[99yam40]

timing light works the same on all spark ignitions.
if it is turning and sparking, you can see it

 

[robert53a]

Thanks 99yam40, I guess I better buy one.

 

[99yam40]

Borrow or renting would work also

 

[robert53a]

I will get a timing light and give it a try. Thanks