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need a 1st gen camshaft cap


Guest Swifty

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I need some help please...does anyone have a VR1300 camshaft cap? These thingies hold the overhead camshaft in place and tie down the valve covers. Correct me if I'm wrong...I'm assuming they are the same regardless of their location on the cam so any one will do. I'm told the 1300s are different than the 1200s though. Yamaha doesn't sell them separately; local wreckers are not willing to open up their salvage engines. Anyone come to my rescue?

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EBay--- I see engines taken apart all the time. Selling tranny and other engine parts. Someone there must have a few of those around. Note: you should get a plastigauge from the NAPA auto for $3 to confirm the clearance is not too tight or too loose. SO get a few to be sure.

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Note: you should get a plastigauge from the NAPA auto for $3 to confirm the clearance is not too tight or too loose. SO get a few to be sure.

 

Agree this has to be checked. So what if it is too tight or too loose how do you adjust it.

 

The lower have of the cap is part of the head, and the cap bolts to the head, and I am not sure about adjusting it anyhow ??

 

Brad

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I would TiG weld that back together. Cam shaft/ cap is linebored/honed for proper straightness. If you do replace with a cap from another engine drill out the bolt holes about ½mm so you can spend several hours locating the center of the cam, and even then Good Luck!

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Hey Dave,

On page 8-4 of the First Gen. Manual, it states that the Camshaft to Cap Clearance should be .0008 to .0021 inches. when you get your caps from one of the members, find the cap that is stamped with the same number you are replacing, (I'd try this one first) install the cap on the cam and torque to 7.2 foot pounds with the plastic gage between the cap and cam. If after removing the cap you find that the plastic gage shows you are in the range of .0008 to .0021 then you should be OK. If the cap is less than .0008 then try another cap. If you can't find one that is in the .0008 to .0021 range then look for one that is greater than .0021. Use a piece of 600 grit wet and dry automotive sandpaper, place the sandpaper on a very flat surface, (a piece of glass works well for this) wet the sandpaper, draw the "legs" of the cap across the sandpaper using equal downward pressure on the cap. Do not rub back and forth, pull the cap in one direction only. After drawing the cap across the sandpaper a few times remeasure with the plastic gage. Keep drawing the cap until it comes into the .0008 to .0021 range. I would personally shoot for .0015 inches. Keep in mind that if you go below the .0008 range, then this cap is junk! So don't be too "heavy handed" while doing this operation. It's better to sand and check for an hour (not that it's going to take that long) than to over sand and scrap the cap out. I have used this method more than once and it has worked VERY WELL for me. It's not perfect but it will do the job nicely for you. If you have any questions, please feel free to PM me. By the way, I have been an Aerospace Machinist for 37 years so I am not suggesting this method lightly.

Earl

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+1 on the fact that they are line bored and unique.

 

I'm not sure if the caps are symmetrical to the extent they can be installed "backward". Normally this is a no-no, but since you're replacing the cap anyhow it'd be worth checking both ways for the best fit.

 

I wouldn't bother having the old cap welded. The distortion to the cap from the welding is likely to be worse than the mismatch from using a cap off another head.

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Hey Randy, check his first post. Pic shows it must have broke either tightening or trying to loosen a valve cover bolt.

 

 

Dan

 

I see that now Dan, thanks. Given the rest of the cap is intact, I wonder if he could do a good epoxy job to restore the wall for the threads for the cover bolt? Maybe even epoxy a stud in and put a nut on top of the cover.

RandyA

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I would TiG weld that back together. Cam shaft/ cap is linebored/honed for proper straightness. If you do replace with a cap from another engine drill out the bolt holes about ½mm so you can spend several hours locating the center of the cam, and even then Good Luck!

 

That's about the only Way to do a smart Repair Job.

 

TIG Weld, even a good two Component Glue will do the Trick. Only other reasonable Way is to replace the whole Cylinder Head.

 

I wouldn't put a Stud in, because you might end up with not getting the Cover on with the Motor in Frame. Just weld or glue the Parts togehter.

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even a good two Component Glue will do the Trick.

Just glue the Parts together.

seriously?

Who else thinks this Squeeze guy isn't lighting up on something illegal?

What glue product would do the trick?

Actually, the part that broke is only holding the threads for the valve cover, not the cam.

If it doesn't work it'd only mean leaking valve cover gaskets I suppose....groan.

Talk to me, you know-it-alls.

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Yes, sure i'm serious. My Father glued the Teeth back in Place on the straight Gear of the Rotary Assembly of his Girder Mast Crane. It held up for one Year each Time on normal use. But this was 30 Years ago !!

 

I can't name the Product, because it's not available in US, but i believe if you look into the Loctite Production Line, you will find the right Stuff there also.

 

You have to be very clean and watch out any Step of the Procedure, but it will work. I think you will need a fitting Tap and retap the Thread after the Pieces are back together.

 

 

I admit, I'm lighting up too much, but nothing illegal, not even the Doormat !!

 

And .... the Part you broke is the upper Part of the Cam Bearing ....

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Like they have all said, once the came bore is machined through the caps, they can only be used in that position and no other one will fit. The ONLY way I would use another cap is to take the head off and take the thing to a machine shop to have them machine it out properly. No guess work on your own. These things take a lot of stresses and if they're out of place, you could wind up with a broken cam or worse.

 

Since all that needs is the little pieces put back, you might try a good welding shop. Even then, once the part had been heated like that, it would be best to bolt the thing down and check the bore dimensions with an inside caliper before relying on it again.

 

I wonder if some JB Weld would work for this. I know machinists who swear by it. I've used it only once in a much less critical situation. The claim is that once it sets up, it's as hard as steel and machines the same too. If you want to try that, I'd drill some small holes in the crack area, and I mean like .040" or smaller. That would give some extra area for the JB Weld to hold the pieces. If any of the stuff gets into the threads, don't try to run the screw through it or the pieces will just break out again. The proper tap ought to be used to clean out the threads. Good luck.

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Another suggestion would be to use a very slight amount of something like anti seaze on a bolt and place it or screw into the threads that are left and then use epoxy around the bolt, making sure you do not get any anti seaze on the areas away from the threads. After the epoxy sets up, unscrew the bolt and you have ready made threads.

RandyA

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Another suggestion would be to use a very slight amount of something like anti seaze on a bolt and place it or screw into the threads that are left and then use epoxy around the bolt, making sure you do not get any anti seaze on the areas away from the threads. After the epoxy sets up, unscrew the bolt and you have ready made threads.

RandyA

 

 

Or the Anti-Seize has set in where the Glue should be ...

 

Or the Anti-Seize Chemicals interact with the Glue in any Direction ...

 

I wouldn't take any chance. The proper Glue will help you out, no Doubt, but if if there goes something wrong, you won't want to clean up that mess and start all over again!

 

Clean up everything, follow the Procedures, let it cure and tap the Thread when setting Time is over. Nothing else.... (Just my Suggestions)

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The Devcon mentioned is some REAL good stuff, I use it at work and it can be tapped. What I will say about welding it, it can be done, but dont let some shmoe do it. The part will have to be extremely clean, Muriatic acid does well with aluminum. It also needs to be pre heated prior to striking an arc. If you have any grease or solvent at all on it the aluminum will pop and your really screwed then. Choose wisely young Skywalker, and may the force be with you....

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Hey Dave,

place the sandpaper on a very flat surface, (a piece of glass works well for this) wet the sandpaper, draw the "legs" of the cap across the sandpaper using equal downward pressure on the cap. Do not rub back and forth, pull the cap in one direction only.

 

Used that method to tighten up some poured rod bearings on an early 3/4T Chevy Carryall with a straight 6. Just sanded the caps until I got the right clearance with plasti-guage. Drove the hell out of that truck for many afterwards. Wish I still had that thing... The AK47 of the truck world.:thumbsup2:

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Hell, back in the day (when safety wasn't as prevalent a concern) I worked at a shop where we used JB Weld to rebuild a variety of parts (on our own project bikes) pretty regularly. I remember a clutch cover that was basically shattered that we reconstructed with the stuff and it held for a good few years - longer than the rest of the bike lasted. Not sure it's strong enough to take the torque needed on the valve cover though.

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Hey Paul,

who is "we"?

inside a motor?

can ya'll imagine the damage in there if the glue didn't hold?

yeeeeouch.

 

Cdn Military (it is in the supply system), that stuff has a NATO Stock #.

 

I also know someone that used it on a cracked engine case (Harley) & re- tapped the hole. I have used it a little, over in Bosnia, as well.

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JB weld has save my a$$ a few times, Got to get it very clean,I would buy the longer drying time stuff and not the quick set.Put you broken peices in first and maybe wrap it together with a rubber band,and fill up the hole with it also,let it set for 24 hours and drill and tap. Im sure you can get Brad t over there to give ya a hand.:stickpoke:

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My thoughts:

 

The caps are line bored and in this way they would be unique to their specific position on that specific engine.

 

The break you have should be able to be welded. I know a few guys that can TiG a pop can back together if you tear one apart. If the welder knows what they are doing and pre heats the part, takes it slow, warpage won't be a problem. Just ask around at the parts stores and such to find who the good welder is. Don't be afraid to pay either, it will definately be cheaper than a head, or re machining the one you have.

 

In my humble but accurate opinion the best thing JB Weld has going for it are the ads on Paul Harvey. I wouldn't use the stuff in the presence of hydrocarbons (engine oil) and it likes to start getting soft at about 250ºF. By 400º, it is back to putty. I just don't think it could take the heat of an engine, nor the expansion and contraction that aluminum goest through in a heat cycle.

 

Probably the worst case scenario woudl be that you have to have that race welded up and re bored at a machine shop, which might run you a couple hundred bucks. Mot sure what a used head goes for...

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