Author Topic: Head rebuild Michigan (Read 3143 times)

Handlebar · « **on:** October 29, 2021, 07:17:26 AM »

Looking for a shop or individual in Michigan to rebuild a 750f head.

Don R · « **Reply #1 on:** October 29, 2021, 07:49:05 AM »

It's in Wisconsin but you might send it to CycleX.

Progas · « **Reply #2 on:** October 29, 2021, 08:16:23 AM »

Send it to Cycle-X, you won't regret it!!

Translations · « **Reply #3 on:** October 29, 2021, 03:52:36 PM »

If you are alright with sending it out I would recommend Schumann Motor Works on Ebay:

https://www.ebay.com/itm/303992040359?hash=item46c7566ba7:g:rX8AAOxyBotTZGo1

He rebuilt my 78 cb750f head and did an excellent job at a extremely fair price. Sent him a pretty crusty head to say the least and when I got it back it looked brand new and was ready to paint out of the box! Even repaired a stripped thread for one of the head studs with a time-sert.

Handlebar · « **Reply #4 on:** October 29, 2021, 05:04:20 PM »

Right on. I was on the phone with them today . He was very helpful ,I will have them rebuild my F3 head. Here it sets before the problem. 10,350 miles

seanbarney41 · « **Reply #5 on:** October 29, 2021, 06:12:40 PM »

You need to educate yourself about the special problems facing cb750f2 rebuilders so that you can make an intelligent assesment of the machinist. The 750k heads really don't have these problems and often need very little special work. There is some good info at the CycleX website.

Handlebar · « **Reply #6 on:** October 29, 2021, 06:43:18 PM »

Sean. I should of been more clear. I talked with Ken at cycle x ,he did explain to me the process that they use. After the conversation I felt pretty confident with them. On the other hand if you know of a more local (mi) shop to perform the work, I am all ears.

ekpent · « **Reply #7 on:** October 29, 2021, 07:28:00 PM »

Why is the head on the bike right now not painted black, is it the stock head or a replacement of some kind ?

Don R · « **Reply #8 on:** October 29, 2021, 10:20:37 PM »

Is it just me or is that an early K head?

Remcod · « **Reply #9 on:** October 30, 2021, 02:35:13 AM »

Indeed, can be a pre 73 head. If you post a picture of the front of the head we can tell

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Handlebar · « **Reply #10 on:** October 30, 2021, 08:25:49 AM »

Thanks gents. Ekpent, great question This very well could be a K head . I also noticed that the intake valve is in fact larger than the exhaust I have loaded a couple of pictures. .

Handlebar · « **Reply #11 on:** October 30, 2021, 08:26:31 AM »

Handlebar · « **Reply #12 on:** October 30, 2021, 08:27:36 AM »

bryanj · « **Reply #13 on:** October 30, 2021, 08:32:38 AM »

Inlet is always bigger than exhaust

Translations · « **Reply #14 on:** October 30, 2021, 09:53:24 AM »

Quote from: seanbarney41 on October 29, 2021, 06:12:40 PM

You need to educate yourself about the special problems facing cb750f2 rebuilders so that you can make an intelligent assesment of the machinist. The 750k heads really don't have these problems and often need very little special work. There is some good info at the CycleX website.

As long as you install stronger guides and upgrade the seals it'll be good and any good motorcycle specific machinist will do his research before hand? You can always take it further, but to do the full CycleX treatment is also going to be a lot of money.

Don R · « **Reply #15 on:** October 30, 2021, 10:23:17 AM »

The fins have ben sanded for sure, from the side in the bike pic it appears to have the extra fin braces seen on early heads. If you have a caliper you can measure the valve sizes. An F2 will have larger valves.

Old Scrambler · « **Reply #16 on:** October 30, 2021, 10:51:58 AM »

Early K head..............hard to fit to an F2-F3 set of barrels...........and the pistons would have to be changed.

So what makes you think the head needs rebuilding? Could be several other problems if the parts are not matched. Sean may be your best local expert to examine what you have.

seanbarney41 · « **Reply #17 on:** October 30, 2021, 10:56:18 AM »

Quote from: Translations on October 30, 2021, 09:53:24 AM

Quote from: seanbarney41 on October 29, 2021, 06:12:40 PM
You need to educate yourself about the special problems facing cb750f2 rebuilders so that you can make an intelligent assesment of the machinist. The 750k heads really don't have these problems and often need very little special work. There is some good info at the CycleX website.
As long as you install stronger guides and upgrade the seals it'll be good and any good motorcycle specific machinist will do his research before hand? You can always take it further, but to do the full CycleX treatment is also going to be a lot of money.

Quote from: Translations on October 30, 2021, 09:53:24 AM

Quote from: seanbarney41 on October 29, 2021, 06:12:40 PM
You need to educate yourself about the special problems facing cb750f2 rebuilders so that you can make an intelligent assesment of the machinist. The 750k heads really don't have these problems and often need very little special work. There is some good info at the CycleX website.
As long as you install stronger guides and upgrade the seals it'll be good and any good motorcycle specific machinist will do his research before hand? You can always take it further, but to do the full CycleX treatment is also going to be a lot of money.

there have been many threads here on this topic over the years. And, I believe, in at least one of them, lies the answer. I found this one.
forums.sohc4.net/index.php?topic=10540.0
I don't think it gives us the best solution to the F2 problem. It just outliines the problem pretty well. Hopefully someone will be along with better search skills than me.

seanbarney41 · « **Reply #18 on:** October 30, 2021, 11:16:56 AM »

Quote from: Old Scrambler on October 30, 2021, 10:51:58 AM

Early K head..............hard to fit to an F2-F3 set of barrels...........and the pistons would have to be changed.

So what makes you think the head needs rebuilding? Could be several other problems if the parts are not matched. Sean may be your best local expert to examine what you have.

Well, I will tell ya. I have not ever actually had an f2 apart further than swapping a damaged cam, rockers and towers. But I have an F3 that is blowing more smoke than is acceptable (really, as a 2t fan I could care less about the smoke, its the 4 new plugs and a quart of oil every 3 or 400 miles that keeps me from riding it!) Also, the pitted valve stems and rocker tips that require a clearance adjustment very frequently and due to the pits, really, can't be done accurately.
I am not very observant about picking out model year differences without parts sitting in front of me to compare.
If Handlebar had posted this a year or so earlier, I would have a stellar machine shop to use right here in Kalamazoo. But alas, the owner has retired.

seanbarney41 · « **Reply #19 on:** October 30, 2021, 11:22:49 AM »

Handlebar, do you know this bike's history? Is it possible the previous owner adapted an early k head to fix the inherent F2/3 valve train problems?

Remcod · « **Reply #20 on:** October 30, 2021, 11:48:11 AM »

Its an early k head for sure. This fin gives it away.

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Handlebar · « **Reply #21 on:** October 30, 2021, 08:39:34 PM »

I do not know the early history of this motorcycle. I acquired it a few years ago, none running with 9,700 on the clock. The previous owner had messed up the valve adjustments,so I pulled the engine had the valves reset and it ran well. Then on a spirted afternoon run it acquired a top end rattle, eased it back home. That was 4 years ago until now. I will say that in the 7-8 hundred miles I was able to put on it ran well. I would like to have it back.

seanbarney41 · « **Reply #22 on:** October 30, 2021, 10:33:14 PM »

You have not figured out the cause of the top end rattle?

Handlebar · « **Reply #23 on:** October 31, 2021, 05:12:56 AM »

No,there was nothing obvious. I am really.starting to wonder.what this head is Some say early K because of the fin design. What ever it is it worked. I must add ,at the time before the problem arose,I was adding a little bit of lead additive to the fuel,upon a friends advise. Could that of loosened things up?

Handlebar · « **Reply #24 on:** October 31, 2021, 05:23:54 AM »

I do not have the head here at home with me, it is still at my mechanics shop. I will get it back in my hands soon, so I can inspect it more thoroughly. Are there any stamps or identifying marks that I should look for?

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Author Topic: Head rebuild Michigan (Read 3143 times)