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1982 XV750 J, Transmission issues? Out of Ideas!

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Re: 1982 XV750 J, Transmission issues? Out of Ideas!

PostAuthor: faffi » Sun Nov 26, 2017 8:01 am

I'm with Greg - see how it goes. It is very likely that the front gasket is blown as well. Both my head gaskets looked like yours.
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Re: 1982 XV750 J, Transmission issues? Out of Ideas!

PostAuthor: TwoJoker82 » Sun Nov 26, 2017 10:56 am

I'll go ahead an pull the other head, and slip off the rear jug. may as well make sure the other cylinder has a gasket, and make sure the rear piston hasn't snapped off or some other oddity! :db:
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Re: 1982 XV750 J, Transmission issues? Out of Ideas!

PostAuthor: TwoJoker82 » Sun Nov 26, 2017 1:39 pm

Thanks Greg,

So, I pulled the jug, found a good bit of very dark oil that collected around the gasket, (and a couple of locator pins?) the piston is in good shape, some obvious heat color on the rearmost side. I did notice that the piston could be pushed a slight bit forward and aft at the top, which i'm assuming is just the heat tolerance.
Otherwise, the rod seems sturdy up and down. It does have some left and right play though. I'm not sure if that is normal for these engines or not. I mean I can wobble the rod directly along the crankshaft maybe a couple mm. The cylinder seems to be ok, no scoring or anything bad like that. worst things I found being a very rusty head bolt, and some light rust marks on the cylinder walls (normal to me for old bikes)

Overall I'm worried by the side to side play of the connecting rod, and the very dark oil chilling around this cylinder. I'm worried It was not getting fresh oil. (If it were fresh it would be gold from the oil I put in?)

I'll pull the other cylinder to compare. Might answer some of these questions.

-Rob
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Re: 1982 XV750 J, Transmission issues? Out of Ideas!

PostAuthor: nanno » Sun Nov 26, 2017 2:00 pm

Hi Rob,

have a look how yours goes and I shall have a look at a new and a used crank and can then probably give you some pointers on how much play is present new vs. used. (Don't worry, not much hassle for me as one crank has to come out of the cases and the other one has to go back in... :bg:

Cheers,
Greg
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

http://greasygreg.blogspot.co.at (My blog - Greasygreg.blogspot.co.at)
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Re: 1982 XV750 J, Transmission issues? Out of Ideas!

PostAuthor: TwoJoker82 » Sun Nov 26, 2017 7:09 pm

Front cylinder proved to be a a huge pain to get free... but I got it! Lots of rust in the channels for the head bolts.

It seems this gasket was about 1/4 present. So perhaps this will fix my issues? did notice a lot more oil in the front cylinder, but I'm thinking this might just be a scavenging issue as I had it tilted forward while working on the rear. All valves seem to be in decent shape, although I would like to get them well cleaned. it seems I might have a valve for the rear that is blocked about a fingernail width open by a ring of carbon.

Both cylinders have the same side to side play in the connecting rods, so I assume that's probably a non issue... As far as the grand scheme goes.

Inspection of the crankcase shows no real worries. I can't see any loos bits or broken metal. I will try to look into the drive train more tomorrow.
Looks like I might just throw it all back together and see what happens.

-Rob
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Re: 1982 XV750 J, Transmission issues? Out of Ideas!

PostAuthor: nanno » Mon Nov 27, 2017 1:31 am

Lapping in the valves etc. isn't a huge job and now that you have everything open and at your disposal, well, it would be a shame NOT to do it. Removing carbon from the valves can be a huge pain, so if you can get a good quality gasket remover, try that. The other thing that is (unfortunately) quite like are bent valves as there's very little wiggle room, if you're one tooth out on the timing.
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

http://greasygreg.blogspot.co.at (My blog - Greasygreg.blogspot.co.at)
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Re: 1982 XV750 J, Transmission issues? Out of Ideas!

PostAuthor: TwoJoker82 » Mon Nov 27, 2017 7:51 pm

Well I finally got the gaskets in the post today.
spent the afternoon cleaning up the valves externally, and then the rest of the heads. Next up will be to finish getting everything back together. both cylinders, heads, and cam sprockets are back on! It took about 3 hours, so not too terrible. will try to get the rest together tomorrow, then pop in the case cover gaskets.
I had a heck of a time getting the heads to set level... the really didn't want to go back down. I suppose the bike just wasn't ready to have an actual gasket again :P

Hopefully I can get the engine back in the bike tomorrow, and see whats up!


Any advice for things to double check before I try to start it? I'm particularly paranoid about timing.

-Rob
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Re: 1982 XV750 J, Transmission issues? Out of Ideas!

PostAuthor: nanno » Tue Nov 28, 2017 3:38 am

Put on the left engine cover and check the timing both on the rotor and the according cam for alignment.
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

http://greasygreg.blogspot.co.at (My blog - Greasygreg.blogspot.co.at)
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Re: 1982 XV750 J, Transmission issues? Out of Ideas!

PostAuthor: TwoJoker82 » Thu Nov 30, 2017 12:46 am

Hello guys

Finally got everything back together. It was a good bit of work to get the gaskets cleaned up! Managed to do both side covers, the cylinders, and the heads. plus new O rings on the valve covers and new gaskets for the exhaust down pipes. She no longer leaks oil, so that's nice. Hauling the engine back into the frame by myself was... fun, but I managed it in the end. I'm working on finishing up the reassembly and hopefully will see If this fixed the issues.

Thank You for your help so far, I'm glad there's such a great place to get help!

-Rob
Be the change you wish to see in this world - Gandhi
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