Cam cap bolt hole stripped

[Guest]

Quick background;
Tore down my 79 GS850 to take a care of oil leaks 3 yrs ago. Due to work schedule and other issues been difficult to work on it and get re-
assemnbled. Couple months ago wife hired a neighbor ( who works at the local Suzuki shop) and his friend to put the engine back together. They got it done in a day. Went out 2 days later to start re routing wiring, etc and found they forgot to put in the valve lifters/buckets(among other things)!! I tore it back down,put in the buckets, and starting installing exhaust cam. Went out this morning to finish and found that 1 of the bolt holes for the "B" cam cap was stripped.
It is the hole closest to the cam chain and sparkplug hole. ( I tried to cut/paste/mark and post a picture of a cyl head but couldn't get 1 quite right)
Would it be okay to run like this or do I need to tear it all down and retap/Helicoil the hole?

Any help is greatly appreciated.

Scott

[loud et]

Hey Scotto.....If the hole could be re tapped in place, go for it!
it sure seems likely the frame will interfere, but if you have a strait shot to drill it, I think you may have a chance at a tap/helicoil. Otherwise you are looking at the classic case of probably replacing the head/base gasket because they will have been disturbed. and then......as they say, you might as well do valve seals and hone and re ring the pistons its a bit of cost but you will be good for a long long time.
The biggest disappointment is the hack job your neighbor did. I hope you are able to approach him to get your money back.
I am not sure about running the bike with one of the four cam cap bolts missing, I would wait for more experience to chime in.
sorry for your crappy situation!
the wrong hands got into your engine

[7981GS]

The factory blind holes can be taped about 10 mm's deeper.

Eric

[hampshirehog]

Another trick is to use a 5/16 BSF tap and fit a new bolt to suit. You could also use a 9/32 BSF or a 5/16 BSW.

[scotto58]

Cam cap hole stripped

Thanks for the suggestions/ideas.
loud-I do have enough room to re tap it. what I'm trying to avoid is having to pull the head to make the repair. I guess I'll grease up the correct size metric tap and have at it.

Scott

[7981GS]

If you have a shop vac handy, it wouldn't hurt to have it in the mix when you pull it out.

Eric

[gearhead13]

I have used 1/4" NC taps on those with some success. Until you tear it apart again a few times.

[Don-lo]

A 1/4-20 sae bolt of the same length (or slightly shorter) will go right in, self-tap, and hold perfectly.

The cause for these kinds of stripping is usually oil in the hole: The bolt will stop turning before it is snugged down, so people keep cranking it down. I use a q-tip to remove the oil.

[scotto58]

Cam cap hole stripped

Eric- I do have 1 and it will be in use if I re tap the hole.

Don-lo & gearhead- I think I'll try Don's suggestion 1st. Seems the easiest 1 to do at this point.

Thanks for all the suggestions.

I'll keep you posted on results.

Scott

[hampshirehog]

Don't use a bolt to self-tap. It will fail, maybe not straightaway but in aluminium it will fail. Do it properly with a tap and it will be as good as new. Use a fine thread and it will be better than new.

[Steve]

And please don't mix other types of fasteners in your metric bike.

We both know that next time you have that apart, you will have forgotten about it. You will curse the "previous idiot (mechanic)" that worked on it and left it so you have to find other wrenches to take the bolt out. THEN, when you go to put it back together, you will have forgotten again, and will stick that 'foreign' bolt down another hole, ruining its threads, and the process continues.

Oh, and even if you happen to remember the 'foreign' bolt, pity the poor guy that buys the bike from you. Then YOU will be one of those dreaded "previous owners".

.

[7981GS]

And please don't mix other types of fasteners in your metric bike.

We both know that next time you have that apart, you will have forgotten about it. You will curse the "previous idiot (mechanic)" that worked on it and left it so you have to find other wrenches to take the bolt out. THEN, when you go to put it back together, you will have forgotten again, and will stick that 'foreign' bolt down another hole, ruining its threads, and the process continues.

Oh, and even if you happen to remember the 'foreign' bolt, pity the poor guy that buys the bike from you. Then YOU will be one of those dreaded "previous owners".

.

Agree 100%

Eric

[hampshirehog]

Agree 100%

Eric

I take the opposite view - it's a good fix, better than a helicoil when done properly. If there's a worry about forgetting what bolt it is then a blob of paint on the head as a reminder works.

Plus hopefully it will be 30 more years before it needs doing again.

[LarryJ]

I'd put in an insert to repair the thread & use the correct original bolt.