A few bolt questions, 1984 K100RT

[Rook]

Apologies if covered in an easily findable thread that I couldn't find, but I have a few questions regarding head bolts as well as dress up bolt kits...

Most important first, I'll be going into the engine to change some things and instead of using new k100 head bolts to button it back up, any issues using the K1100 head bolts if shortened?  I'm mainly on about the different profile in regards to what kpartsholland has on offer...


K100

Vs

K1100


From what I've seen around the web, from about 93 is when the head bolts went from that K100 profile to the nearly full length thread in the second pic.  Dunno if that's anything to do with the K100 ending but I'd imagine so...

I'm a machinist by trade and shortening the bolt with negligible heat is doable, and I've shortened head bolts before with no issues, but as I'm new to this engine are their any concerns?  Oil galleries?

The K100 bolts are nearly twice the price, and I don't mind paying if I have to, but I'll save money if possible.

Speaking of, and on to the next topic... .are there any definitive lists in regards to what you'll get with the stainless bolt kits?  All I've seen are just bags with bolts and no descriptions, so if I have to compile a list so be it... I work in a machine shop and have access to pretty much whatever I need, so just thought to save time I'd ask...

Thanks!

[Laitch]

If you're looking for a stainless steel bolt list, here's one made for pre-09/1985 K100 models. Click the link under the Documents heading.

[Rook]

If you're looking for a stainless steel bolt list, here's one made for pre-09/1985 K100 models. Click the link under the Documents heading.

Outstanding.  Many thanks, saved me an afternoon 

...now to get all the measurements... 


In regards to the head bolt question, I'm going to give it a go regardless, same thread pitch and the threads where the shank is on the k100 bolt isn't restricting anything from what I've been able to find.

Will post back here next year and after about 100 miles with compression figures after it's all finished.    Thanks for looking

[Laitch]

 

[daveson]

Why are you getting head bolts, are you replacing the head gasket? I'm assuming that the engine hasn't been cooked. Another option is to use the existing bolts. Lots of people have used the original bolts again without problems, including torque to yield bolts. If the longest head bolt isn't any longer than say 0.2mm of the shortest bolt, I will guess that you can use the existing ones. Let's say one of them does come loose, one of the good things about bricks is that it's pretty easy to get access to the head bolts, to replace them. That's a bonus, whichever way you choose to go. For this reason I think it's also worth trying to adapt K1100 bolts to suit.

How did you shorten the bolts previously?

[Rook]

Why are you getting head bolts, are you replacing the head gasket? I'm assuming that the engine hasn't been cooked. Another option is to use the existing bolts. Lots of people have used the original bolts again without problems, including torque to yield bolts. If the longest head bolt isn't any longer than say 0.2mm of the shortest bolt, I will guess that you can use the existing ones. Let's say one of them does come loose, one of the good things about bricks is that it's pretty easy to get access to the head bolts, to replace them. That's a bonus, whichever way you choose to go. For this reason I think it's also worth trying to adapt K1100 bolts to suit.

How did you shorten the bolts previously?

Only recently bought my K, an '84 with just under 21k miles, but when I was looking it over prior to purchase I saw signs that the water pump had gone, had a look at the oil and was juuuuust very slightly off with some mild milky residues so I'm operating under the assumption the bike could have been cooked a touch.  Bought the bike for 1200 and always went into the purchase with the intention of stripping and refreshing as needed so it's no biggie.

I scoped the cylinders and compression was fine, didn't notice any scoring but IF I flip the coin and elect to go into it I will be replacing the pistons with K75 tops and new rings.  I've always used new when it comes to head bolts that weren't ARP, just a thing I've done since my first engine and I don't mind in this case.  It's a mixed bag from what I've read in regards to some snapping on the way out but loads of others reusing theirs with no issues whatsoever, so I just want to go ahead and do new on the first, and hopefully only, rebuild.

Last time I shortened head bolts I used an Okuma Genos L-400.

As this is my first K, I've no experience with the subtleties and niggly bits when it comes to their engines... yet... but I'll get there.  Will measure the depth of the hole if/when I actually get in there and see if shortening is necessary.  Would be nice to find out for sure though and share the results here so people aren't pigeon-holed into buying only K100 head bolts at 11-12 quid a pop.

[Kaos]

When it comes to buying all bolts, my best suggestion is to paste the oem number of the bolt in Google, some shops do offer cheaper than kparts in Europe. Like hobbyist.nl.
Also Hedgehog garage sells the stainless bolts for a decent price with the baggies tagged on where they should be installed. -Trust me, i know bolts-
Milky oil could also be a sign your waterpump (rubbers) need some love as coolant is getting into the oil turning it Milky white (salad dressing effect) and it is also the place of personally start looking.

But also, up here somewhere, there was stated you can reuse them. Which Ive done on all my k's after either replacing the gasket or the cylinder head.

[Rook]

When it comes to buying all bolts, my best suggestion is to paste the oem number of the bolt in Google, some shops do offer cheaper than kparts in Europe. Like hobbyist.nl.
Also Hedgehog garage sells the stainless bolts for a decent price with the baggies tagged on where they should be installed. -Trust me, i know bolts-
Milky oil could also be a sign your waterpump (rubbers) need some love as coolant is getting into the oil turning it Milky white (salad dressing effect) and it is also the place of personally start looking.

But also, up here somewhere, there was stated you can reuse them. Which Ive done on all my k's after either replacing the gasket or the cylinder head.

Gonna raid the shop coffers first as we have probably 80% of the bolts in both shiny and black variants, then shop around for the remainder.  No set in stone timeline on the build but the cosmetics will all be last, so quite a few months away and plenty of time to source all I need.  Currently stuck on 3x nice K75 pistons and if I don't get another 3x in just as good condition for a similar price I likely will hold off on pulling the head and just keep everything in reserve as far as the head bolts/gaskets go... no reason to tempt fate for a slight performance upgrade that can be done way down the line if wanted...

Already bought a pump rebuild kit as was my first thought also, regarding the rubber.  Hopefully it's only that, I may make a new shaft/gear myself for it and replace while I'm in there, screw those prices man...  hilarious how much they charge for some of this stuff and not being funny I've already started making a few things in Solidworks to maybe remedy it for some folks in the future if it's viable on my part to do so...  this shaft and gear for starters... also haven't seen anyone taking advantage of the bosses down near the clutch actuator to mount a slave, had ideas on this area for a while that would get rid of all that hardware and maybe do away with the clutch pushrod seal.

Getting ahead of myself, long way to go yet tbh.  Not had a chance to really tear into the bike yet except on paper as been waiting on a big shipment of our belongings to finally get here from the States, but that's being delivered this Thursday...  I'll get on it as soon as the dust settles and the 130+ boxes and totes are condensed a bit and my garage space is clear again in a week or so, promised the missus I'd hold off on pulling it apart until afters...     Sooooooooooooo looking forward to having my welder and Shapeoko available again and the small mountain of K100 parts keeps growing...