Maxes-out around 55mph. 81 CB750 DOHC

[barnett468]

It's the engine. Tested in park, and going 55 I idled the engine.

I get buzzing from it, and most the vibration comes from the tank. Bars too though.

Checked engine mounts, didn't get a sync in this weekend, will this week though.

ok, well the end of your crank on the stator side may be bent.

 

[Joseph New York]

ok, well the end of your crank on the stator side may be bent.

Sorry for the delay, had to focus on my 650, which is getting nowhere fast.

How can I check to be sure the crank isn't bent? I'm sure that is a very dumb questions, so please be gentle. It's the side that was hit pretty hard and I replaced the entire stator cover/housing.

As to the gearing, my rear sprocket says 43. If I want more torque on the high-end, I could replace it with a larger one with more teeth right? I found a 48T on eBay... I couldn't see the teeth count for the front sprocket, but I'm assuming its 18.

On another note, I pushed her a lot harder recently on the highway and went around 65 for about 45min. I don't know how much harder I could have pushed it as she was vibrating hard, but I had to try. When I was done, the valve cover gasket around 1 & 2 was covered in splattered oil. See pics... Only seems to happen in high speed. The oil actually splatter up to the top left of the tank.

I'm not sure the needing a new valve cover gasket could be causing my issues I created this post about, but I'm going to replace it ASAP and check the valve clearances.

 

[Ply318ci]

I think that is your valve cover/cam cover that is leaking the head gasket is below your exhaust. I would replace both and this would be a good chance to check out the condition of your heads and Pistons might help out.


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[Joseph New York]

I think that is your valve cover/cam cover that is leaking the head gasket is below your exhaust. I would replace both and this would be a good chance to check out the condition of your heads and Pistons might help out.


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Haha of corse, Thx, edited.

You think I should replace the head gasket too? I'll look into that too


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[Ply318ci]

It is really up to you. I am no expert (if you read my own thread you will see that) but if it isn't to big of a job and you have the time and money it might be a good idea, could be your problem is in the heads and pulling them will give you a chance to check them out. I would at least replace the valve cover gasket and inspect the cams for any oddities.


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[barnett468]

You think I should replace the head gasket too? I'll look into that too

if it ain't broke, why fix it?

 

[Joseph New York]

if it ain't broke, why fix it?

It's fine, but he saying while I'm at it... I just ordered a valve cover anyways.

I'd like to order a bigger rear sprocket and was thinking of grabbing a 48t I found on eBay. I have a 43t. Would I need to get a new chain too?


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[alzcbz]

Did you ever figure out if you were actually able to shift through all the gears?
Just went back to the first page of this thread. That stator cover took quite a hit. It's a good bet that the stator and maybe the crank have damage.
I would address this first before you put anymore money into this engine. If the crank is bent, you will need to do a full tear down, if you intend on repairing it.

 

[Joseph New York]

Did you ever figure out if you were actually able to shift through all the gears?
Just went back to the first page of this thread. That stator cover took quite a hit. It's a good bet that the stator and maybe the crank have damage.
I would address this first before you put anymore money into this engine. If the crank is bent, you will need to do a full tear down, if you intend on repairing it.

I get through all the gears no prob. Stator was untouched in the accident lucky, and is fine and tested. I will take a look at the crank still. The $20 for the gasket isn't a big investment and the engine is totally worth it IMO. She's actually my most reliable bike. Runs like a top.