My limited mechanical abilities have left me stuck at this point. I'd like to measure crank run out for a future 107 build but I'm stuck at my comfort level at this point.

Is there way to to get the crank run out without pulling the cams? I'm don't wanna mess with timing etc.

How do I spin the crank? Pull plugs and crank with starter?

I do know how to measure run out on the bearing surface with dial indicator, it's getting to the bearing surface.

 

the cams are really pretty easy if you just follow the instructions with a manual.to check,pull the plugs,jack rear wheel up ,put in 5th (or 6TH) gear and spin wheel.use a piece of steel bolted to one of the cover bolts with a magnetic indicator

 

Cam plate

 

The cams are timed by aligning the dots on the inner sprockets and you can check runout without removing the cams. Some will argue that the cam plate must be removed for a more accurate measurement and I would agree; however, checking with the cam plate on will tell you a lot.

The outer sprockets are indexed; the rear cam sprocket is indexed to the cam and the pinion sprocket is indexed to the pinion shaft so, once removed, they will only go back one way. I would suggest that you pay attention and put the chain back so it is rotating in the same direction as it was when you removed it.

The attached photo shows a way of measuring with the cam plate removed but you can setup something similar to check with the cam plate in place. If runout shows to be .002" or less, I would assume OK for the new build and geared cams if you are considering running geared cams. However, if runout reads .004" or more, geared cams are not an option and a check with the cam plate removed would be a good idea before making a decision on whether or not to have the runout addressed for the new build.

Like Kirby says, pulling the cam plate is not a big deal; more work for sure since you have to loosen the rocker arm support plate, pull the pushrods and hold the lifters up with magnets but, with the manual, not a tough job......

 

I agree it doesn't look hard, I'm just gun shy having never done it. I know there is alot that could go wrong. I've watched a few videos. But thats not experience.

Have 60,000 plus on it.... no problems, but a fresh top end wouldn't hurt.

I don't think I'm going gear drive.


Looking at cycle rama 574, tman 555 tqster, and drago 580.

Nothing outrageous, just wanted to know run out before starting. I don't wanna spend the money to split cases/ss crank, but I don't wanna grenade a fresh top either.

So if the crank is to far out I'll prob do nothing for another year till funds allow a bottom end.

 

Exhaust was already enough trouble...front 2 nuts were seized. Used a bolt extractor on rear of front head, and h<br/>ad to weld a socket onto the very front stud, then the bolt tore apart. Not much room between the frame in that location. Still havent got the studs out...

 

For me it is.. It's easy to pull the cam cover but a real PITA to pull the cam. You have to pull the lifters up out of the way. The only way to accomplish that is by pulling the pushrods.. Not adjustable? Rocker covers and supports need to come off unless you have adjustable pushrods. Still you'll need to hold the lifters up or remove them to pull the cam plate.. Why go through all that work? Only 10 screws hold the cam cover on. Exhaust is typically the hard part.. The trick is understanding cam chain alignment and what the cams are doing when you pull the sprockets and chain. You need to unload any turning motion on the valve train. The picture shown above is pretty close as it means the front cylinder is sitting at TDC overlap and rear in on compression.. It's a location where you can turn the motor over without banging valves against pistons. Once the sprockets are removed you really need a test indicator (kind with a little arm and ball on the end) to get into the pinion / cam plate bearing surface. With plugs out, rear wheel off the ground and motor in 6th you can rotate the crank and check runout.. Of the motor stops turning at some point, chances are you are not at tdc overlap front cylinder..

Once you are done making measurements, turn the crank back to the same location it was and slip the chain and sprockets back on (hopefully you left the chain on them and didn't let the teeth slip).. Anther thing to point out is that the cam and crank bolts need to be Red locktited. It's important that the oil be removed from threads.. The sprocket bolt on the crank opens up into the oil passage that goes to the rod bearings so it will bleed oil for a while.. You can let the oil dribble out for a while then clean with a Q tip and brake-clean. I wouldn't squirt brake-clean into the hole as it will wash oil off the rod bearings. Anyway after that you follow the manual on assembly (except for case screw TQ (do only 80 in/lb on them) and you are done.

I've not done a chain drive in a while but have done gear cammed bikes recently.. One was good, 2 were bad..