Yamaha XS 400 DOHC - starter turning but not engaging

[Mihail Petev]

Hi there,

First post on the forum - I have the following problem - i have an 88 or 86 (not that it should matter) DOHC SX 400 and i have been debugging not starting problems. I tested the starter solenoid - all works. Tested the starter - it also turns. My initial assumption was that the starter was not deploying but after removing it, it would appear to me that this particular starter is not the retractable type as there is a cogwheel right in front of it which seem to always be engaged with the starter.

Do you have any suggestions or a diagram of the right side of the engine block so i can see what the engagement mechanism is.

Thanks a lot

Cheers

 

[tstidham]

I assume the dohc uses a similar starter clutch as the sohc motor with spring loaded rollers. The springs can brake and the rollers done grab the crankshaft. Some have had the housing crack too causing a similar issue. I had two of my springs break leaving the clutch to sometimes grab and mostly just spin. I found springs of McMaster-Carr that were close and it's been fine since.

 

[Mihail Petev]

Yeah i saw there are some repair kits on ebay with spring replacements. Going to open it over the weekend and see what the situation is.
After I try to figure out why the hell are they using Philips head screws

 

[tstidham]

Those are JIS head screws and do yourself a huge favor and purchase a proper JIS screwdriver off Amazon or similar shopping site. It makes removing them infinitely easier than using a Philips and won't bugger the screw head.

 

[Mihail Petev]

Ah good point been on my shopping list for a while actually so i guess now is the time

 

[Mihail Petev]

Ok the screwdriver worked like a charm should have gotten one from those long ago.



Now the next problem - does anyone have any experience removing the starter clutch. To me it would appear that it actually requires complete engine disasembly see the photos I can see it trough the hole but can't access it. Also doesn't seem to be a accessible from the other side so my only assumption is that I have to separate the top and bottom engine pieces or am I missing something

 

[Mihail Petev]

Update - yes the engine needs to be split for replacing it - however I had luck by removing the alternator and wiggling the rod a bit