'86' V65 Magna build

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I'm thinking of taking the front head off and checking it all out.  Pretty big task that makes me more nervous about putting it back together than pulling it apart lol.  While It's off it will give me a chance to fix that fuel tube and o-rings on the carburetor. 

If anyone has any idea where to find the valves for the V65 I'd appreciate it?  I've tried BikeBandit, and CheapCycles, and EBAY motors.  I've also called the largest motorcycle junk yard in California right here in Fresno (APF) and not even they have any valves for the V65.

[roboto65]

http://cgi.ebay.com/ebaymotors/Honda-V65-Sabre-Cylinder-Head-Exhaust-Valves-Springs-_W0QQcmdZViewItemQQitemZ390233057601QQptZMotorcyclesQ5fPartsQ5fAccessories

Try that not any new one I found yet but the search continues 

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Thanks for looking Robo!  I just found a pretty decent front head with the valve train still all attatched on EBAY for like 50 bucks including shipping off of an 84 magna.  There are a few options there as far as used goes.  I just wonder if a used set up will have the same outcome mine had, but if that's all there is to get then I'll have no choice but to go the used rout lol.  Thanks again for helping out!

[roboto65]

Well until you get the head off you really do not know what you need but extra parts never hurt either well except the wallet LOL

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Well, I got it all apart in about 3.5 hours, and OF COARSE there is no obvious problem.  I did notice a 1" piece of the airbox gasket missing, most likely making a bit of a vacuum leak in the intake manifold.  The fuel leak in the carbs is coming from the middle fuel pipe joining the #2 to the #4 carb.  Other than that, there is no bent or burned valves.  The springs all return the valves to full close, there is a tiny bit of scoring on the #2 outboard camshaft retainer grove and some obvious carbon build up in the #2 head from not firing correctly.  So if the mechanics of the head assembly is all pretty good, then the problem must be in the carbs.  The #2 cylinder is shiny and clean with no oil whatsoever so I don't think its the rings.  Could the fuel leak be preventing enough fuel from getting to that specific carb and cylinder I wonder?

[hootmon]

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Man, you are living up to your name!!! I don't know how familiar you are with this type of work, but I won't say I wouldn't do what you did, but I probably wouldn't calm enough to take pictures and type!!!

Good Job so far..

I'd probably take the head down to a "Head Shop" and see if they could Magna Flux it (Or whatever they do today) to check it out for cracks, etc.. They may be able to see/identify something you can not..

[dgc67]

Be glad it was the FRONT head.  So, then why the heck was the compression down on that cylinder?  hmmm...

[roboto65]

I did notice a 1" piece of the airbox gasket missing

I am going to say that that is your hesitation problem right there any airleaks at the airbox will cause you grief it does not take into account the fuel problem but I bet you fix the fuel leak and gasket and she will be back to her mean self 

[lragan]

I did notice a 1" piece of the airbox gasket missing

I am going to say that that is your hesitation problem right there any airleaks at the airbox will cause you grief it does not take into account the fuel problem but I bet you fix the fuel leak and gasket and she will be back to her mean self 

I am still at a loss to understand why this would reduce the measured compression, Alan.  Can you please explain?

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Hootmon, I have absolutely no idea what I'm doing lol.  This is the first time I've ever tore into a motorcycle engine, but typically if I see it come apart, I understand how it goes together... for the most part!

Robo, I agree with that airbox leak being my hesitation problem.  I told my wife I was glad to see that gap in the gasket and also there was a small crack in the airbox itself because that at least explains the hesitation and wierd idle I would have coming off of the throttle at times.

Iragan, I'm sharing your confusion still.  I have no idea now what could have been causing the compression to be cut in half compared to the other cylinders.  That carbon build up on the valves and #2 piston show me that it's not burning efficiently though.  Do you think that a vacuum leak up top could cause the #2 carb to act funny and somehow allow the intake valves to vacuum lock open or something, allowing the exhaust stroke compression to escape... Lord I don't know lol.  The head gasket looks pretty petrified but I dont see any exhaust marks on it like it was escaping through the gasket. 

I think I'll take it to a local shop and at least have them lay eyes on it.  I have to just be missing something.  Thanks for the input guys!

[Greg Cothern]

Maybe a weak valve spring???  If you have it this far apart might as well go the rest and replace all gaskets, seals, etc etc. 

[roboto65]

Explanation is that I was talking about the hesitation he had when running I did not explain the compression loss anywhere as this has nothing to do with the hesitation heck it might be a stuck or broke ring hate to say that but maybe if the head checks out.

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Robo, I didn't mean to confuse all the comments together, I'm just plain ol confused about the compression problem myself.  That's all I meant, I didn't mean to imply that I was confused with anything you had written.  I did press on the valve springs a bit and they all seemed to be equally as strong.  The rings are certainly a suspect... I just really hope not lol.

[roboto65]

Oh no it was not meant for you  it was meant for Lawrence. 

[lragan]

OK, I will accept full responsibility here for scrambling the symptoms/diagnoses chart.  Sorry, Alan.

I am more concerned about the compression issue (probably because it has more expensive implications) than I am about some vacuum leaks that you have identified and will inevitably fix.