Author Topic: F2 Rings and Intake Boots (Read 2059 times)

Mandic · « **on:** January 07, 2011, 11:37:02 AM »

Does anyone know where I could locate some F2 intake boots and rings for my bike? I have a 77 CB750F, and am popping the engine out to rebuild the head. While doing so I am thinking I may as well throw new rings in it.

According to the service info I have, the engine only has 13k miles on it, but the valve seals are shot so I am completely redoing the head with parts from Cycle X. However unless I find some major cylinder wall issues I am thinking I will just hone the cylinders and re-ring it. Compression readings are good across the board on it, though it was been a while since I did a test to say what they were.

Problem is I am having trouble locating a ring set that says it works for the 77 750F, which makes me ask, are they really different? I know the pistons are different, and the head parts are different, but are the rings different as well?

brandEn · « **Reply #1 on:** January 07, 2011, 11:45:06 AM »

OEM piston rings for the 77-78 F models are harder to find than Bigfoot. I am rebuilding my 78 F now and ended up going with the CycleX 836 kit just because its one of the only options for us F'ers.

Same goes for the intake boots. Ebay or this forum. They are discontinued.

Flying J · « **Reply #2 on:** January 07, 2011, 12:10:20 PM »

I have a used set of stock pistons and a NOS set of standard bore rings i would sell. PM me if intrested

Mandic · « **Reply #3 on:** January 07, 2011, 05:38:13 PM »

I really don't want to go to an 836 right now. Mainly due to expense. But at the sametime, supposedly the engine only has 13,000 miles on it. So why bore it out if it doesn't need it? I'm hoping to just get the cylinders honed and throw new rings in on the existing pistons.

wohali · « **Reply #4 on:** January 07, 2011, 07:01:29 PM »

Rings for an F2/F3: http://forums.sohc4.net/index.php?topic=36531.0

http://www.totalseal.com/ "Price is $122.56 for a set to cover all four pistons with a 2 piece oil ring. Part number: S1796"

Or, you can get the pistons grooved and use the K6 ring set.

If it turns out the gap on my pistons won't allow me to reuse my rings, I'll be going with the Total Seal rings.

For the boots, try soaking in Oil of Wintergreen and hot water. Search on "Wintergreen" on the forum for many, many threads speaking well of this technique.

Mandic · « **Reply #5 on:** January 07, 2011, 07:07:34 PM »

Thanks again, first thing monday I will order new rings. Hopefully in a week or so my engine will be torn down, get all the parts to my machine shop for a clean up and hone and back together asap!

Flying J · « **Reply #6 on:** January 07, 2011, 07:14:20 PM »

Anybody want stock 77-78F rings i have a set for $100.

Mandic · « **Reply #7 on:** January 07, 2011, 07:21:48 PM »

Wrong rings for me anyway. But would be a great deal for someone who needs them!

kmb69 · « **Reply #8 on:** January 08, 2011, 06:05:07 AM »

PM sent for rings.

cheapride · « **Reply #9 on:** January 08, 2011, 08:39:42 AM »

Quote from: Mandic on January 07, 2011, 07:21:48 PM

Wrong rings for me anyway. But would be a great deal for someone who needs them!

Why are these incorrect. 77-78 f2 f3 cb750f used the same rings. Right?

Brent

Flying J · « **Reply #10 on:** January 08, 2011, 08:41:46 AM »

Yeah, im not sure what he is talking about. Part numbers are correct.

Mandic · « **Reply #11 on:** January 08, 2011, 09:10:32 AM »

I don't know there were 2 different part numbers 77 to 78. If you look at the parts break down anyway. They are probably the same just an updated number or something.

mick750F · « **Reply #12 on:** January 08, 2011, 11:49:08 AM »

They are currently out of stock but you might check with them to see if and when carb insulators will be back in stock.

http://www.classicmotorcyclesolution.com/1_7_Products.html

Mike

Mandic · « **Reply #13 on:** January 10, 2011, 07:20:21 AM »

Just got off the phone with Keith at TotalSeal. The salesman I spoke to first told me they never sold those rings, so I jumped to Keith who knew right what was going on, ha. Anyway it ended up being $132. Not sure if that included shipping or not. He also said they don't have them on the shelf so it will take a few days to get me the parts I need, but they will ship by middle/end of the week.

Thanks guys!

brandEn · « **Reply #14 on:** January 10, 2011, 10:51:15 AM »

Thats good info. I really wish I knew that a few weeks ago! Oh well, I am sure the 836 kit will be fun.

Mandic · « **Reply #15 on:** January 10, 2011, 12:44:41 PM »

The engine in my bike supposedly only has 13,000 miles on it. The valve seals leak real bad when you are riding it but no other time, so I am just freshening things up. 836 would be fun, but I am plenty happy with the power I had before. With the new rings, Cycle X valves, and Web Cam I am installing now, I don't see myself wanting for power anytime soon.

wohali · « **Reply #16 on:** January 10, 2011, 01:29:15 PM »

Mandic have you checked your valve stem-to-guide tolerances? The exhaust guides can go way out of spec in just 4000-6000 miles and can damage your stems as a result.

My engine has about 45k miles on it and I have to replace the guides. I may also be forced to replace the valves...

Mandic · « **Reply #17 on:** January 10, 2011, 03:09:31 PM »

I haven't disassembled the engine yet. I got the entire kit from Cycle-X. New guides, seals, springs, retainers, and valves.

The bike sat for a LONG time before I got it. I think since the early 90s or late 80s. In that time the valve seals could have easily hardened up and just not do their job anymore. Either way I am replacing everything to play it safe.

steam-powered man · « **Reply #18 on:** January 10, 2011, 04:02:17 PM »

have a set of rubber boots that connect the carbs to cylinder, nice shape, with oem clamps. $12 plus shipping.

kmb69 · « **Reply #19 on:** January 11, 2011, 12:56:43 AM »

Payment sent last night. Check your PM and email.

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Author Topic: F2 Rings and Intake Boots (Read 2059 times)