'84 1200 engine for a '82 GW

[canuckxxxx]

OK, I squirted some oil in each cylinder and checked compression again. Only small improvement...like 90psi up to 120.

So to confirm that the rings are leaking big time, I screwed in a fitting I have that screws into the plug hole and has an air fitting on the end so I can put air pressure to the cylinders. Air regulator turned to about 30psi because the air pressure will try and turn the engine too much pressure will make things go flying. I put a socket with long handle on the crankshaft bolt to keep the engine from turning. I turned the engine over until an intake valve just closes and the rocker has slack put the air to that cylinder. I did this on all cylinders and in each case the only air you could hear hissing is from the crankcase. You can hear at the oil fill plug opening.

air fitting 1

• canuckxxxx
• Jul 11, 2015

air fitting 2

• canuckxxxx
• Jul 11, 2015

So I am pretty convinced that the rings are leaking big time.

Joe, I will take some close-ups of the cylinder walls when I take the heads off.

Brian

 

[joedrum]

well yes i agree ...i also think this motor has sat a long time with out moving ....and a long time for surfaces not to operate and would effect compression big time ...so i dont agree you can trash a motor without trying something to improve it .. stuck ring would compromise compression completly and come back as soon as it is free and cylinder walls are cleaned down to the surface only.....hmmmm i think it still time to move on with this project ...strip it down to short block and turn by hand and feel for loosenest in the lower end ...watch the pistons at top ...ck and see if they have same turnaround time ..to conferm no play in rods on the cylinders ....good or bad its for you to make sure of it ... i dont see a deal stopper yet.... opcorn:

 

[slabghost]

joedrum » Sat Jul 11, 2015 2:35 pm[/url]":2rr6k0ru]
well yes i agree ...i also think this motor has sat a long time with out moving ....and a long time for surfaces not to operate and would effect compression big time ...so i dont agree you can trash a motor without trying something to improve it .. stuck ring would compromise compression completly and come back as soon as it is free and cylinder walls are cleaned down to the surface only.....hmmmm i think it still time to move on with this project ...strip it down to short block and turn by hand and feel for loosenest in the lower end ...watch the pistons at top ...ck and see if they have same turnaround time ..to conferm no play in rods on the cylinders ....good or bad its for you to make sure of it ... i dont see a deal stopper yet.... opcorn:

:good: I agree. If there's no slop in piston movement some cleaning and running will likely bring it right back.

 

[canuckxxxx]

I did the bottom end looseness test when I first stripped down. Could not detect any looseness by moving crank back and forth and watching and feeling action of moving parts. I think the bottom end is OK.

So for stuck ring is the cure to run the thing and they will eventually unstick?

thinking...

Thanks Joe for the encouragement.

Brian

 

[canuckxxxx]

Slabghost, I was posting my reply when yours came in.

I wiped the cylinders down good before I put the heads on because the PO had put oil in the cylinders for long term storage. I wanted clean cylinders for true comp. test.

So, I'm thinking just put engine in bike and run. Really don't want to take heads of since it's all torqued down with new H gaskets. Not sure what glaze looks like but there didn't seem to be anything on the cylinder walls.

Thanks
Brian

 

[dan filipi]

I would run it.
I have had 2 engines with low compression in the 90's that came up to 165 after miles.

 

[joedrum]

i was thinking heads were off this motor already ?...

 

[canuckxxxx]

OK, guys. I've come this far I may as well take it to the end.

Will, keep posted. BTW my single carb manifold bolts right up.

Brian

 

[Ansimp]

Running with ATF in the fuel will definitely improve stuck rings. Low compression will only give less horsepower, increase fuel consumption and consume oil if it is worn piston rings.

 

[slabghost]

In that case Brian run it! It may take a few miles to free those ring but they pretty much always do. 4 oz of atf in the oil wouldn't hurt in cleaning and freeing up deposits.

 

[canuckxxxx]

Yes, I'm going ahead with the 1200 engine. :music2: I must admit that, after the compression test, I was resigned to putting everything back on the 1100 and calling the whole project a failure but all you experienced oldwingers have convinced me to give it a fair try. :thanks: The bike should run well enough to get me through, what is left of summer and if it still looks like a loser then I can do something else over winter. :builder:

I did a trial fit of the rear case from the back of the 1100 to the 1200. Perfect fit: cable clutch actuator works on 1200 clutch and the drive shaft for the pulse generator slots right in. Just have to clean the old gasket stuff off the 1100 cover and bolt it on. The gasket that is left on the back of the 1200 looks to be unbroken so I will leave it and use it. k:

Also looking at a supply point for coolant for my single carb plenum since the connection I used on the 1100 won't work because of the external oil lines on top of the 1200. I think I can put a "T" and some fittings where the temperature gauge sensor screws into the thermostat area. One thing I learned with the plenum heat is that 1/4" lines are big enough to supply heat do I will use smaller fitting this time.

Looking at the timing belt covers: the 1200 covers will present some problems. Eric, has already pointed out the on the right side he had to grind some away to clear the frame. On the left side, with the 1100 cover, I could route the coolant return past the front of the cover to the water pump. There was a nice little space that lined up perfectly with the water pump fitting.

return plate 1 welded on bike 3

• canuckxxxx
• Feb 7, 2014

I don't think I will be able to do that with the 1200 cover because it sticks out more at that point. Now I am thinking that I will try and put the 1100 covers on. The outside bolts will line up for each cover but the inside bolts are out a little bit. Also there will be about a 1" gap in the middle. Will see what I can come up with. :headscratch:

Brian

 

[joedrum]

its what i did ...use 1000 or 1100 timing covers all things said its quit the mod ....it requires either cuttin motr flange or timing cove flange and yes there shot and inside holes dont line up ...i my case theres no inside bolts used and the 1" gap is still there ... iwouldnt suggest this is ideal ..but i havnt had a problem here yet ... not a easy mod ....it also involves back timing cover mod on left side ...charge forward brian

 

[ekvh]

It's what I have as well. The one inch gap is in a sheltered area. Right now, mine are open.

 

[canuckxxxx]

OK so here is how the 1100 belt cover look on the front of the 1200. Joe, you mentioned cutting flanges, etc...not sure what cutting is required. These covers just bolted on. Inside bolt don't line up so won't be used. 1" gap in middle...will cover with aluminum tape.

belt cover 4

• canuckxxxx
• Jul 12, 2015

belt cover 3

• canuckxxxx
• Jul 12, 2015

belt cover 2

• canuckxxxx
• Jul 12, 2015

belt cover 1

• canuckxxxx
• Jul 12, 2015

Thanks
Brian

 

[Ansimp]

Looks good Brian :good:
Covers are mainly a safety hazard protection feature :yes:

 

[ekvh]

Mine was an 85 and I had to do something with the back plates. I can't remember right now. I didn't think they would fit. Guess I did it the hard way.

 

[canuckxxxx]

'84 1200 seems to be different, very similar to 1100.

 

[dan filipi]

The 84 covers are year specific.
I found this out when sourcing a pair for the front drive ignition mod I did.
The FI back plates look different also.

 

[ekvh]

Forgot you switched to an 84. If you are wondering, you can go to your first post and edit the title from there. It would keep us folks with Oldzheimers memories on the right wavelength.

 

[canuckxxxx]

ekvh » Mon Jul 13, 2015 5:25 am[/url]":3vpvmu3l]
Forgot you switched to an 84. If you are wondering, you can go to your first post and edit the title from there. It would keep us folks with Oldzheimers memories on the right wavelength.

Good thinking Eric. :thanks: I will try.