Yepblaze
Lieutenant Commander
- Joined
- Jun 1, 2001
- Messages
- 1,686
I have recently acquired an 81 DT85 (8501-001734) as a resurrection project.
Well, it lacked spark, and through diagnostics found it to need a CDI switchbox and a couple of ignition coils.
Now, after replacement of these components I have great spark, but the timing for all three cylinders appears to be about 30-50 degrees retarded. I have indexed and checked the flywheel, it's timing grid, and piston locations to verify and they are all correct.
Upon extensive (well extensive enough) research I find that somewhere in the model range they changed the triggerbase/flywheel as a pair and I may have from some previous owner received mismatched components.
I have seen a difference between my flywheel and it's internal ring magnet, and it's relationship with the keyway by way of a mechanical drawing in a manual,
but have not seen (as of yet) a timer base with the control arm and it's relationship to the 3 pickup coils (yet) with the corresponding difference.
I think I can possibly change one, or the other to correct this issue.
I have called around looking for parts and most suppliers want to sell the pair for about $300. this is currently way out of the budget for this motor after already dropping $200 for the CDI and coils.
That and I still have no confirmation that the timing variance is actually a parts mismatch.
I'm including a couple pics of what I have at hand.
Perhaps someone has dealt with this issue, can shed light on this, or has a motor in the bone yard with parts available at a very reasonable cost that I can acquire to help me correct my issue. yepblaze@hotmail.com
These components (by way of my research) are somewhat compatible between the dt75 and dt85 through about 1980 and about 1984.
Well, it lacked spark, and through diagnostics found it to need a CDI switchbox and a couple of ignition coils.
Now, after replacement of these components I have great spark, but the timing for all three cylinders appears to be about 30-50 degrees retarded. I have indexed and checked the flywheel, it's timing grid, and piston locations to verify and they are all correct.
Upon extensive (well extensive enough) research I find that somewhere in the model range they changed the triggerbase/flywheel as a pair and I may have from some previous owner received mismatched components.
I have seen a difference between my flywheel and it's internal ring magnet, and it's relationship with the keyway by way of a mechanical drawing in a manual,
but have not seen (as of yet) a timer base with the control arm and it's relationship to the 3 pickup coils (yet) with the corresponding difference.
I think I can possibly change one, or the other to correct this issue.
I have called around looking for parts and most suppliers want to sell the pair for about $300. this is currently way out of the budget for this motor after already dropping $200 for the CDI and coils.
That and I still have no confirmation that the timing variance is actually a parts mismatch.
I'm including a couple pics of what I have at hand.
Perhaps someone has dealt with this issue, can shed light on this, or has a motor in the bone yard with parts available at a very reasonable cost that I can acquire to help me correct my issue. yepblaze@hotmail.com
These components (by way of my research) are somewhat compatible between the dt75 and dt85 through about 1980 and about 1984.
