Author Topic: 750F thread? (Read 167132 times)

gearhead ed · « **Reply #625 on:** March 31, 2011, 10:06:16 AM »

Back in the day on my first 78f I put in a diy baffle that I copied off of a kerker. This time I made a baffle within a baffle. The smaller straight thru baffle has a diverted plate that is operated by a remote cable. In the closed mode the exhaust goes into the second baffle that has some sound deadening material wrapped around it. In the open mode it goes straight tru for more sound. What I'm trying to do is have my cake and eat it to. In the quite mode I will not annoy the neighbors. In the open mode I should get the cagers attention in the next lane that is taking on the cell phone.

Don R · « **Reply #626 on:** March 31, 2011, 11:08:24 AM »

I made a new muffler. it's stainless and matches better in the sunlight. Sounds fantastic.

gearhead ed · « **Reply #627 on:** March 31, 2011, 11:33:37 AM »

That looks great! Did you weld up the reducer or did it come that way? You should install a name plate on it and call it the Don RRRR! What kind of baffle are you running?

Freaky1 · « **Reply #628 on:** April 03, 2011, 06:54:10 PM »

I know those of us with these superior "F" bikes have a common issue and I'd like some input. Que the organ music, carb insulators, mine are not dead and in comparison to some I've seen they are in pretty good shape but they are cracking inside. I have advice from Hondaman on the xylol and wintergreen mixture to soften them up but this is only a hold over and new ones just do not exist. I was thinking about trying to find a company that could make some, unless someone has already beat me to this. If so, speak up, if not I was thinking of trying to find someone that would make some, anyone interested??

Don R · « **Reply #629 on:** April 03, 2011, 09:44:48 PM »

The pipe is a stainless truck tip and the baffle is a car side pipe glass pack insert. I made a spare if anybody wants to try one. I have about 60 dollars in it not counting labor. My prototype in the picture cost about 120 but I found wholesale parts suppliers. I have an idea for variable back pressure but mine runs so good I haven't messed with it.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #630 on:** April 03, 2011, 10:47:27 PM »

Looking forward to seeing and hearing it in person next month.

cheapride · « **Reply #631 on:** May 17, 2011, 10:28:29 AM »

Hey guys and gals, I have a 1978 f2 and am thinking about replacing the clutch this winter when I tear it down. What is everyone else running for a clutch. It doesn't seem to slip but since the engine will be apart I am thinking I need to replace the clutch too. A friend has an extra APE clutch but I don't know if it will be a direct replacement.

Thanks,
Brent

wohali · « **Reply #632 on:** May 17, 2011, 10:49:48 AM »

Do you just mean the clutch plates? They're the item that will wear.

Getting into the clutch basket doesn't require splitting the crankcases, but you do need a special tool (or a home-made one) to get the clutch nut off. Be careful and loosen the 4 lifter bolts (that hold the springs in) gently, a quarter turn each, or you'll snap the lifter plate in two!

Mine looked fairly good when I pulled them, only a teeny bit of wear on the one "special" F2 plate (with the spiral cuts in it on one end). At some point in the future I'll pick up a new set of plates...they weren't slipping before I took her apart, though.

cheapride · « **Reply #633 on:** May 17, 2011, 11:19:23 AM »

My clutch seems fine but the bike has 30,000 miles on it. The ape clutch kit is just the fibers and it comes with new springs and 2 new plates. Some one said that you need another stock plate to make this kit work in the f2.

Brent

Silverback · « **Reply #634 on:** May 17, 2011, 11:29:32 AM »

Quote from: turkey4me on March 27, 2011, 02:12:37 PM

Update on the sprocket wear...

I removed the chain guard for a closer look and the inside of the rear wheel sprocket is severely worn. This tells me the front is either too far out or the back sprocket is too far in. Using a laser sighted straigt edge on the rear sprocket face, they are off 3/8". Holy smokes!!! I have to say there is no way the front can be off that much. Has to be the rear. I double checked the rear wheel adjusters and they are dead even. Then it dawned on me this is not a factory set up. The rear wheel is a drum brake comstar from a K model. Not your typical F setup with a disc brake. Anyone know if this might be the issue? All I can think of doing at this point is to remove the rear sprocket and install 3/8" spacer to move the sprocket out.

You didn't say which direction the rear sprocket was off (in/out). If you contact Ken at CycleX he has an offset front sprocket that pushes the front sprocket out 10mm (3/8"). If you have an early F, which is it looks like in the pictures, this will certainly be the easiest fix to your problem.

Silverback · « **Reply #635 on:** May 17, 2011, 11:32:54 AM »

Quote from: Don R on April 03, 2011, 09:44:48 PM

The pipe is a stainless truck tip and the baffle is a car side pipe glass pack insert. I made a spare if anybody wants to try one. I have about 60 dollars in it not counting labor. My prototype in the picture cost about 120 but I found wholesale parts suppliers. I have an idea for variable back pressure but mine runs so good I haven't messed with it.

Do you mind letting us know who this supplier is? I'm looking to build a few mufflers and yours looks great!
Thanks!

Jerry Rxman Griffin aka MuthaF'er · « **Reply #636 on:** May 17, 2011, 01:31:24 PM »

Quote from: Don R on April 03, 2011, 09:44:48 PM

The pipe is a stainless truck tip and the baffle is a car side pipe glass pack insert. I made a spare if anybody wants to try one. I have about 60 dollars in it not counting labor. My prototype in the picture cost about 120 but I found wholesale parts suppliers. I have an idea for variable back pressure but mine runs so good I haven't messed with it.

Hey guys,

The pipe Don has made is really nice and not obnoxiously loud. Anyone that needs a replacement I'd highly recommend it. He said he has a few made up. If Don doesn't get $100 you get off REAL cheap!

JoeHip · « **Reply #637 on:** June 11, 2011, 03:55:47 AM »

Quote from: ZanVooden on March 11, 2011, 09:22:09 AM

So Im currently getting ready to rebuild a '78 750F and have done a couple compression checks and now im wondering what you guys think.

I did the first two right after I got the bike in the garage and got these results:

#1 #2 #3 #4
110 100 85 85 (psi. typical)
Then added some oil to the cylinders
#1 #2 #3 #4
150 145 150 145 (psi. typical)

I then added a little seafoam to each cylinder and let it sit for a couple days and then turned the engine over a bit to get out what was in there and did a compression check again and here's what I got:

#1 #2 #3 #4
120 120 118 115 psi (typical)

They are all within 10% of each other now, but is this high enough?

whats up with the seafoam, what does it do?
please explain?
thanks

tweakin · « **Reply #638 on:** June 11, 2011, 05:10:20 AM »

1977f and 1978f

Newby_j · « **Reply #639 on:** June 11, 2011, 05:40:42 AM »

Thought I might be able to add a few pics here of my 76

Newby_j · « **Reply #640 on:** June 11, 2011, 05:41:37 AM »

Quote from: tweakin on June 11, 2011, 05:10:20 AM

1977f and 1978f

Wow Freaking Gorgeous!

BeSeeingYou · « **Reply #641 on:** June 11, 2011, 11:21:59 AM »

Quote from: JoeHip on June 11, 2011, 03:55:47 AM

Quote from: ZanVooden on March 11, 2011, 09:22:09 AM
So Im currently getting ready to rebuild a '78 750F and have done a couple compression checks and now im wondering what you guys think.

I did the first two right after I got the bike in the garage and got these results:

#1 #2 #3 #4
110 100 85 85 (psi. typical)
Then added some oil to the cylinders
#1 #2 #3 #4
150 145 150 145 (psi. typical)

I then added a little seafoam to each cylinder and let it sit for a couple days and then turned the engine over a bit to get out what was in there and did a compression check again and here's what I got:

#1 #2 #3 #4
120 120 118 115 psi (typical)

They are all within 10% of each other now, but is this high enough?

whats up with the seafoam, what does it do?
please explain?
thanks

What is the mileage on the bike?

The Seafoam may help loosen up any rings that are stuck from long term storage. The actual readings are less important than the fact that they are within the 10% level. Due to the very small amount of volume you are measuring unless you account for the volume of the gauge and tubing it throws off the reading. Depending on how you did your test and what type of gauge you used those readings don't look all that bad. I would be more concerned with the top end as the 77/8 F bikes had the well known valve guide issue. Again this will depend on the mileage of the bike but the usual cure is new valve guides.

Sometimes for a bike that has been sitting a long time a short period of running will also improve the situation by reseating and unsticking rings.

BeSeeingYou · « **Reply #642 on:** June 11, 2011, 11:30:24 AM »

You do great work, Tweakin.

JoeHip · « **Reply #643 on:** June 12, 2011, 06:40:10 AM »

so the seafoam is used to loosen up the rings?
thanks srust58

shark · « **Reply #644 on:** June 12, 2011, 01:23:45 PM »

Quote from: Don R on April 03, 2011, 09:44:48 PM

The pipe is a stainless truck tip and the baffle is a car side pipe glass pack insert. I made a spare if anybody wants to try one. I have about 60 dollars in it not counting labor. My prototype in the picture cost about 120 but I found wholesale parts suppliers. I have an idea for variable back pressure but mine runs so good I haven't messed with it.

Do you still have any to sell?

tweakin · « **Reply #645 on:** June 12, 2011, 01:33:06 PM »

Thanks!

Forum member brandEn built the orange one so I can't take credit for both.

Quote from: srust58 on June 11, 2011, 11:30:24 AM

You do great work, Tweakin.

shark · « **Reply #646 on:** June 12, 2011, 01:33:52 PM »

Here's mine. 1976 CB750F

Got the front brake to stop dragging and, charging/electrical system working well (not perfect but the best it's ever been). And now I'm riding it more, the little holes in the muffler got bigger.

Frustrating, but a whole lot of fun at the same time.

BeSeeingYou · « **Reply #647 on:** June 12, 2011, 07:50:04 PM »

Quote from: shark on June 12, 2011, 01:33:52 PM

Here's mine. 1976 CB750F

And now I'm riding it more, the little holes in the muffler got bigger.

Frustrating, but a whole lot of fun at the same time.

I patched a hole in the muffler on my 76F (on the backside underneath) with a small piece of stainless sheetmetal and JB Weld. Very small holes could be just the JB. It will get you a few more years out of it and since it is already a bit cosmetically challenged who cares.

shark · « **Reply #648 on:** June 13, 2011, 05:11:20 AM »

I was thinking of the muffler patch stuff to get me by. Never considered JB weld.

The one patch on the muffler is so ugly, anything I do won't be noticed.

jdubb1977 · « **Reply #649 on:** June 13, 2011, 08:55:22 AM »

posted these pics elsewhere on the forum, but thought they should definitely be on the "F" specific thread. my '76 F!

News:

Author Topic: 750F thread? (Read 167132 times)