GS850 (1979) - Three stripped bolts

[d19407]

Hello Fellow GS Riders,

I am about to perform some planned maintenance and pull the head on my 1979 GS850 to do a valve check/repair/restore/replace. While I have the head off I want to address a few other small problems which I would like some advice on please.

Referring to : http://www.bikebandit.com/1979-suzuki-gs850g/o/m12821#sch257261

I have three stripped bolts – the first is the bolt (item 11) at the front of the engine. After referring to Bike Cliffs web site - I believe this bolt is an M6x45 with a standard pitch (sorry if that’s not the correct terminology – my expertise in this area is a little fuzzy)

Also, I have two other bolts – one on the far left and one on the far right of the cylinder (item 10) again I believe this is an M6x35 with a standard pitch.

Question: Has anybody attempted to tap these out to a larger size? If yes then can you share the results with me please? Any kind of input is welcome. I did search the forum but can’t find anything specific.

I’m interested in the diameter of the bolts used. I was thinking of tapping them out to M7. Will M7 be a big enough step up or do I need to go to M8? I obviously have concerns about going too large and cracking/breaking something.

One more thing: Assuming its M7 will I be able to simply use an M7 tap or will I need to drill the hole first (6.5mm perhaps) – I was thinking that given the originals are M6 and stripped and this is aluminum it would be okay to simply tap out to M7 without drilling.

Any thoughts on this matter would be appreciated.

Regards, Andy.

[7981GS]

Stripped or broken?
Those bolts are tiny yet critical in the head not leaking oil.

Eric

[Steve]

Referring to : http://www.bikebandit.com/1979-suzuki-gs850g/o/m12821#sch257261

I have three stripped bolts – the first is the bolt (item 11) at the front of the engine. After referring to Bike Cliffs web site - I believe this bolt is an M6x45 with a standard pitch (sorry if that’s not the correct terminology – my expertise in this area is a little fuzzy)

Also, I have two other bolts – one on the far left and one on the far right of the cylinder (item 10) again I believe this is an M6x35 with a standard pitch.

First of all, if you were to refer to the parts fiche on ANY of the other vendors, you would see the official Suzuki part numbers, which have the sizes encoded.

Bike Bandit is occasionally good for some accessory stuff, but their parts numbering system is goofy, and their parts pricing is high, the second-highest of any vendor that I know.
Unless you happen to see a good deal on tires or clothing or something like that, they don't really deserve much attention.

Bolt #11 is part number 01517-06308 which tells you that it is 6mm diameter bolt that is 30mm long. Yes, standard 1.0 pitch.

Theh other two bolts, #10 are part number 01517-06458 which tells you that they are 6mm dameter, 45mm long. Still the standard 1.0mm pitch.

There is no real need to enlarge the holes. One reason is that it can be very difficult to find 7mm hardware and 8mm holes will likely be too big.

As 7981GS asked, though, are your bolts just stripped or are they broken in place?

.

[MisterCinders]

Based on the Suzuki part nos., No. 10 (01550-06457) is M6 x 45. Looks like No. 11 (01550-06307) is M6 x 30. Both should be standard x1 pitch.

How badly are the threads in the head stripped? If there is no bolt broken in there, I'd consider chasing the threads with an M6x1 tap and replacing the bolts.

Edit: Sup Steve? Hi-five.

[d19407]

Thanks for the quick replies guys.

They are stripped not broken off and while I don't have any significant oil leaks it is weeping out of the gasket (which I replaced last year).

I guess at this stage I will try to track down some hardware and shoot for 7mm - the bolts are just spinning in the hole so I just don't think that there is enough meat to just run a 6mm tap over the same hole - . I'm just concerned about breaking/cracking something.

So if Bike Bandit is not a preferred vendor - who do you recommend?

[Steve]

So if Bike Bandit is not a preferred vendor - who do you recommend?

I just looked back through your few posts and found that, somehow, you have escaped BassCliff's Mega-Welcome. (<-- click the link)

There is a LOT of good information there, along with some of our favorite vendors, some of them have commentaries, explaining why or why not to use them.

When you think you might have absorbed all the information there, grab a chair and a pot of coffee, you haven't even started yet.

Click HERE to go to his "little website" to see the rest of the library. Be sure to bookmark it, you will be returning there often.

.

[d19407]

Hello Steve,

Actually I didn’t escape the mega welcome – I’m not sure where it went to, but not only did I get my welcome - I used all the information I was given to completely overhaul my gs850 – front wheel to rear wheel (excluding transmission and valves) – I did everything on the list. My 850 was very neglected when I got it, and it’s my opinion that it had not seen any real maintenance for 30 years. So I did everything on the list, and now I use it every day to ride to and from work – starts first time – I have full power throughout the entire rev range (darn fast for a 30+ year old bike) and it runs like a charm – even in the 106 degree San Antonio weather.

All of this was made possible because of the information compiled by BassCliff and the knowledge given by this great forum – I couldn’t have done it without that.

Cheers to all those who contributed – you have my deepest thanks.

FYI I do have BassCliffs web site book marked and I visit there on a regular basis, and I saw the preferred vendor list too – I however did not realize how big the price difference was – I am going to order my parts for my upcoming top end overhaul from Parts Shark – although I have heard they can sometimes be slow to deliver.

Regards, Andy

[Rover]

We like Boulivard Suzuki for OEM parts.Z1 Enterprise also for vintage bike parts.