Author Topic: 78 CB750F "Modular-ish" cafe build? (Read 59345 times)

brandEn · « **Reply #250 on:** March 22, 2014, 04:00:15 PM »

Search the forum for my leak free top end thread for some tips. As for torque on the HD studs it's much more than stock. I think like 18 ft lbs and stock is 13. Those are off the top of my head....

madScientist · « **Reply #251 on:** March 22, 2014, 04:38:06 PM »

Thank you as always Branden. I found your thread and will read through it.

Now that it's warming up I'm ready to ride this one and get the CL350 project moving.

tweakin · « **Reply #252 on:** March 22, 2014, 07:20:59 PM »

Yes, I do 18 - 20, let it sit overnight and then re torque.

Quote from: brandEn on March 22, 2014, 04:00:15 PM

Search the forum for my leak free top end thread for some tips. As for torque on the HD studs it's much more than stock. I think like 18 ft lbs and stock is 13. Those are off the top of my head....

madScientist · « **Reply #253 on:** March 23, 2014, 06:33:47 AM »

Perfect! If i remember right I think i did like 14lbs so that might be contributing somewhat. I think I've set on pulling the head off. I'm pretty much there anyway after taking the rocker train out. What's another 16 or so nuts?

Do I need to acquire new pucks and exhaust seals (assumed yes). What about the head gasket? It's a Cometic.

Likely have it taken down in the next few days and want to make sure I have all the bits necessary to quickly get it back together. I hate leaving pistons exposed.

tweakin · « **Reply #254 on:** March 23, 2014, 07:03:13 AM »

If it were me and I was chasing a leak I would replace all the gaskets I remove. You could probably reuse the pucks if they were new when first rebuilt the engine and look good on disassembly.

Good luck bro.

madScientist · « **Reply #255 on:** March 23, 2014, 07:33:59 AM »

Then that's what I'll do. Thanks Tweak! The pucks were new but, i'm not going to pinch penny's on this so I'll get them new as well.

madScientist · « **Reply #256 on:** March 24, 2014, 07:49:39 AM »

Parts ordered through Dynoman.

-- Cometic head gasket (non MLS this time)
-- 6 pucks
-- exhaust seals

Also topped up my M6 and M8 helicoils

Parts should be here in a couple days and I'll get to it.

brandEn · « **Reply #257 on:** March 24, 2014, 08:45:14 AM »

Man I have been in your shoes a couple times! Just take your time and all should be well.

SOHC4 Cafe Racer Fan · « **Reply #258 on:** March 24, 2014, 10:51:54 AM »

It sucks but once these issues are fixed you will be totally focused on the 350!

madScientist · « **Reply #259 on:** March 29, 2014, 07:26:06 PM »

Well there are two ways to do things...the right way and again.

It was apparent after pulling the head that the gasket was leaking. There was a head bolt near it that felt a little on the loose side. I had only torqued them down to 13ft lbs when I did it so I'm going to add that to the mix.

It was a good thing I did this though. After removing it I noticed a couple of the cam cradle bolt threads were knackered up so they got heli-coiled. Plus...i'm ashamed to admit this...but I had the posts on the wrong side of the head. I had them on the intake side. They are now on the exhaust side where they belong. Plus that explains why it's a beotch to put the plugs in it. I also put a little Permatex sealant on the post bolts in accordance with Brandens leakproof head thread. Everything spec'd out as flat.

I have the head back on with the head nuts torqued to 21ft lbs and the 4 centers to 8.5ft lbs. I'll double check it tomorrow and then put her back together. After a good cleaning...that thing is hella dirty...

I'm still waiting on exhaust crush washers to show up. Dynoman was out of them so I had to order them elsewhere. I'm hoping they show up Monday. Debating putting the headers back on with the old washers still in it...supposed to be nice on Monday and I'd REALLY like to ride to work. We'll see...dont want to rush it and knacker something else up.

seanbarney41 · « **Reply #260 on:** March 29, 2014, 07:47:16 PM »

I have re-used copper exhaust gaskets successfully many times. As long as you don't bend them up too much when picking them out, just flip 'em over on re-installation. They also can be annealed, heat 'em up with propane or other torch and dunk 'em in water.

madScientist · « **Reply #261 on:** March 30, 2014, 05:09:04 PM »

Head gasket changed. I've gone about 20 miles on it and so far so good. I do have a slight exhaust leak but I'll deal with it. The new washers should be here in a few days and the weather is going to turn crap by Wednesday.

On a side note...my new neighbor had a friend show up today on one of the prettiest 77 Goldwings I've seen in a long time. The attention to detail on this thing was amazing. I neglected to get a photo :-(

Hopefully I'll see it again and will snap one then!

Hon3ybadger · « **Reply #262 on:** April 09, 2014, 03:55:43 PM »

What happened to all your pictures? I need to see them again, especially the cafe'd seat pan! that was an ingenious design.

madScientist · « **Reply #263 on:** April 10, 2014, 05:50:30 AM »

Sorry about that. I was organizing my photobucket account to make it a little more manageable. I kind of figured it was going to break the links. I've gone through and fixed them by adding in the album name.

Hon3ybadger · « **Reply #264 on:** April 10, 2014, 06:11:46 PM »

Was it you MadScientist or someone else who did a Modular build with a cut down F seat? I can't find those photos anywhere.

And on your seat swap, the airtech seat would contact the seat lock. Thus the reason you made it removable. In your opinion would it look clean to notch the seat base and leave the seat lock alone?

madScientist · « **Reply #265 on:** April 11, 2014, 05:33:14 AM »

Twas not me. I didn't want to mess too much with good original pieces. Seat cowls, side covers, etc for the fact that they are getting crazy hard to find and I would rather good pieces go to people who're going to restore these old girls. That said I kept my original seat and rear cowl to put them on if I want. Which I will do when I have a chip fixed in the cafe cowl.

Yes the airtech seat would make contact. I didn't want to notch the cowl because I felt it would take away from the clean, smooth lines that the cowl and tank put together. The tank on the F is pretty "boxy" and the airtech helps form a pretty straight line from the front of the tank all the way to the tail. I didn't want to disturb that line.

Hon3ybadger · « **Reply #266 on:** April 12, 2014, 01:23:32 AM »

Ok. I will keep digging through the forum for whoever that was that cut down the seat pan. The reason I ask is because, like you, I would like to keep good original pieces untouched. But the seat and cowl I have are beyond saving. I found an all original complete 76 seat and cowl with trim and strap in a local shops rafters. Probably been up there my wole life judging by the dust on it. I'm afraid to ask them what they want for it.

I totally agree with your point on how the seat lines flow from the tank lines. I've been considering an Airtech seat myself. Problem is the frame just got powdered. I kinda did things backwards.

madScientist · « **Reply #267 on:** April 12, 2014, 05:26:09 AM »

Did you leave the pedestal as well?

I have found that fiberglass, even though its messy, is fairly easy to work with. You could probably fashion up your own cowl to work with the existing components.

Hon3ybadger · « **Reply #268 on:** April 17, 2014, 12:02:47 AM »

Yes. I left everything on the frame original. I considered making my own seat pan and cowl out of sheet metal and considering how my bike budget is going that might be my only option.

madScientist · « **Reply #269 on:** May 01, 2014, 05:50:55 AM »

A friend of mine from work wanted to try out her new camera lens so I got this nice photo of the bike and me...

madScientist · « **Reply #270 on:** May 02, 2014, 04:41:32 PM »

So I just got back from a ride. I was cruising around when the bike dropped a cylinder. I was on the highway and couldn't just stop to check it so I nursed it back home. The cylinder seems to intermittently drop in and out which leads me to think it's an ignition issue.

I shot it with the temp gun and it looks like it's the #1 cylinder that's going in and out. as it was 50 degrees colder than the rest. #4 seemed to be fine so i dont think it's a coil. I'm going to do some investigation but might post in the help section.

This is on a Pamco. I'm not ruling the carbs out either and they are due for a sync. I'll report back when i have more info.

70CB750 · « **Reply #271 on:** May 03, 2014, 04:30:30 AM »

Looking great, hope you sort out the cylinder soon.

What pipes are those? Cyclex?

brandEn · « **Reply #272 on:** May 03, 2014, 04:59:37 AM »

Probably something simple like a loose bullet connector. Hopefully anyways! Good luck and keep us posted for sure.

madScientist · « **Reply #273 on:** May 03, 2014, 06:16:22 AM »

Those are CycleX "Tri-y" pipes. They sound pretty great too.

Yeah that's what i'm thinking as well so first order of business today is to go over the connectors to the coils and check the plug wire connections. I'm also going to swap out the plugs. Start with the simple stuff.

SOHC4 Cafe Racer Fan · « **Reply #274 on:** May 03, 2014, 07:17:47 AM »

Quote from: madScientist on May 03, 2014, 06:16:22 AM

Those are CycleX "Tri-y" pipes. They sound pretty great too.

Yeah that's what i'm thinking as well so first order of business today is to go over the connectors to the coils and check the plug wire connections. I'm also going to swap out the plugs. Start with the simple stuff.

It could be bad (internally cracked) plug wire, too, so check out the wire and the connector.

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Author Topic: 78 CB750F "Modular-ish" cafe build? (Read 59345 times)