Tear-down in progress..

Sorry for the extended delay. Stuff happened. Back to work.

Got my parts from XJ4ever and some from PartsnMore. All the parts arrived in perfect condition. I did have a couple problems with the orders. I had Len ship the parts to the wrong address (my fault). Luckily, I was able to get them from the address I had them shipped to. Len was more than willing to help in any way he could, for which I am grateful. I also received a wrong part from PartsnMore, part code mixup at their end. They sent out the correct part quickly, at no cost to me, and even let me keep the wrong part they sent (a new starter relay for my model bike). I would recommend both sellers, and plan to buy some piston rings next month from Len.

Wizard, thanks for the advice. I'll try that. Just haven't gotten to the head work yet.

Successfully replaced the primary chain guide, and reinstalled the starter clutch (with renewed pieces). Getting the guide in there without removing the crank was a bit tricky. Honestly, I don't see how you would replace the guide without splitting the case. I suppose it is possible, but splitting really isn't that tough. Just time consuming and organization-intensive. I don't think you need to disassemble the top end to do this (head, block), though removing the engine from the frame would obviously be necessary.

I'll be joining the case halves tomorrow. Any recommendations here? I imagine I need some sort of gasket solution on the mating surfaces, but I wouldn't know which one.

 

Permatex makes a grey Gasket Maker, it's listed on their website and is about $8 where I live. Yamabond in cheap clothing. Get new o-rings for the oil galleries, seals for the shafts and you should be good.

 

So, I used the gray gasket material, and all looks well. New o-rings too. I'm at the valve stem seals now, and a little puzzled. The Haynes manual pretty much skips right over this step, listing only a picture, and a caption telling you to replace them.

I've managed to replace two so far, but I'm mangling them with a set of pliers just to get them out, and pushing them in with my thumb. I haven't damaged anything yet, but with this method, it seems just a matter of time. Is there a prescribed method to removing, and installing, these seals?

 

Went ahead and yanked the remaining six off without drama. Finished working on the head. Once I cut out a spring compressor tool out of some PVC tube, things went rather smoothly.

Installing piston rings now. But I've got a question on the base gasket. I got copper gasket material for the head gasket, read a suggestion for that somewhere. Should I be using this for the base gasket as well? I believe I read somewhere that the base gasket gets no gasket solution, but I just want to confirm. Thanks.

 

My seca 650 ,1982 , had a jamed up shifter,only had first and part of neutral, took out a broken chunk of the rubber starter clutch guide from the shift barrel,now it shifts fine. Can this bbike be run with this broken guide,some call it the primary chain guide, I would imagine parts of the guide are still bolted in place that would still provide some guidance. Am I just wishful thinking?

 

Without part of the guide chain will slap around and remove the rest of the guide and nasty things can happen. It's a major tear down , maybe start looking for donor engine. 750 motor bolts in just jet change or carb swap as well.

 

Ride it until the winter. In the meantime get the Factory service manual and the Haynes and begin reading on the teardown procedure. You can do the job over the winter in about two or three weekends. A used engine might get you by, but the primary chain guide in it is going to be just as old, and therefor just as likely to fail.
Rebuild the starter clutch while you are in there.

 

True, Moe is right old motors have old parts. So for the motor pick up a 750 and do it up as Moe stated then you can have the best of both, new motor and more go-go!
I am looking for donor for my seca .....
Must have more POWER

 

Is there not an oil nozzle that will need to be replaced if the chain rubs it for too long?
I suppose this is dependent on how much of the guide has disintegrated?

 

Yes and Yes. The oil nozzle is quite thick so it will take a while before it gets turned into junk.

 

I got this bike as a trade for a snowblower,it was to be a parts bike for the other 1882 seca 650 that I have had since new. So I am not sure I want to tear it all down to replace the guide. But seems to run to good for a parts bike! Thanks for the input.

 

You'll have a spare engine that is ready to go when the guide in your runner fails.