Author Topic: 78 CB750F "Modular-ish" cafe build? (Read 59347 times)

madScientist · « **Reply #225 on:** August 23, 2013, 11:53:18 AM »

Thanks bud! It's a blast to ride. I need to get it up to the dyno to put a final tune in those carbs. They feel good but could probably be better. The Seat Guy Jon has the pan and cafe cowl and should be getting to it soon which will be VERY exciting! I dont much like the stock seat. It just doesn't feel right to me.

I was rummaging through an old laptop i had and found these photos of it from LONG ago. I'm guess this was around 2007 or so when I bought my house and brought it down to STL.

Check out that ugly a$$ fairing

madScientist · « **Reply #226 on:** September 02, 2013, 05:00:16 PM »

I decided to fix the leaky valve cover today. Figured it'd be an easy pull it up, replace the gasket, put it back down kind of thing. After i got the cover off, everything looked good....except for a broken cam holder bolt. That's kind of an odd thing to see isn't it? It was the bolt (not the post) on the immediate right hand side of the gear.

I pulled everything apart, replaced the broken bolt, degree'd the cam and put it all back together. However i'm trying to figure out why that bolt broke! There has to be something underlying that had to help it. That doesn't seem like a bolt that would just break on its own.

Could the cam chain be too tight? Was it just a weak bolt? Shaft flex or something? I rechecked everything spec wise and it all checked out. All those bolts and nuts are torqued down to 8 - 8.5 ft lbs.

I have everything back together and it runs great as always. I double checked each bolt before putting the cover back on and they are all okay at this point. I figure i'll ride another 500 miles or so and pull the cover off again for another inspection.

On a more pleasant note...here are some pictures sent to me by "Jon the Seat Guy" who's making the seat :-D

SOHC4 Cafe Racer Fan · « **Reply #227 on:** September 02, 2013, 07:39:43 PM »

The seat looks nice.

Zaipai · « **Reply #228 on:** September 02, 2013, 08:13:21 PM »

Quote from: madScientist on September 02, 2013, 05:00:16 PM

On a more pleasant note...here are some pictures sent to me by "Jon the Seat Guy" who's making the seat :-D

Yup great looking seat. Same guy that did mine I love it and the work was just awesome. You should love the craftsmanship on it.!

.: Scott :.

madScientist · « **Reply #229 on:** September 29, 2013, 05:11:20 PM »

I got the seat on Friday! Swiftly mounted it up and LOVE it! I wasn't sure about the brown with all the black in the bike but I think since it's sitting in the blue/silver it looks REAL nice. The craftsmanship is great! I highly recommend him "Jon the Seat Guy". I plan on using him to make the seat on the CL350 street tracker...and probably all the other bikes i have in the build queue.

In the next week I'm going to try and get out to some nice country side and get some good pictures of it...you know...not sitting in the garage or driveway. I also intend to take it to vintage bike night next Monday.

I have also determined the 125 mains in the Mikuni's are too big. Up over 90 the wideband tanks to around 10.8 or so which is too rich for my taste. I've ordered 122.5's and 120's to try out.

Here's some pic's of the new seat!

madScientist · « **Reply #230 on:** October 08, 2013, 07:52:18 AM »

Changed the mains down to 122.5. Haven't had the chance to open it up so see the improvements. I might have to go down to 120's.

It was cold this morning so i put the cover over the oil cooler. It definately helps it warm up. In 47 degree weather this morning it was at operating temps in 5-10 mins. Versus yesterday when it took me about 15 minutes (while driving) to warm it up.

Here are some more pics at my office:

If i can get outta this place at a decent hour i've found a nice country-ish setting to take some more pics.

brandEn · « **Reply #231 on:** October 08, 2013, 07:59:47 AM »

I love your bike, simply awesome. I'm kinda partial to these F2/F3 tho...
I still would love a set of those carbs but its not in the budget. Gonna go with the stockers on my K4 for now.

SOHC4 Cafe Racer Fan · « **Reply #232 on:** October 08, 2013, 09:38:04 AM »

Freakin' gorgeous. BOTM material.

sethdhawkins · « **Reply #233 on:** October 08, 2013, 10:19:22 AM »

Chase,

What are you reading with the 122.5 mains? I appear to be just a tad lean.

Seth

madScientist · « **Reply #234 on:** October 08, 2013, 10:33:52 AM »

Thanks a bunch guys! I'm hella proud of this thing! I'm really happy that I found this community as the inspiration to do this came from a lot of the bikes in the projects area.

Seth - i havent opened it up with the 122.5's yet but with the 125's above 7k / 100mph i was reading ~11. My estimation is that i should be closer to 11.5-12 which is more where I want to be. I still need to get up to the darn dyno to really zero in. Time has not been on my side though...

sethdhawkins · « **Reply #235 on:** October 08, 2013, 10:47:11 AM »

Roger that!

cheftuskey121 · « **Reply #236 on:** November 04, 2013, 06:16:58 PM »

Hey mad, I am going to be going through your build thread snagging up ideas. yours, tweakins, brandens, and doctor ds F are what inspired me to get one. I love the sporty look and stance. I will be picking your brain on how you did things. this is a new set of rules to learn for the F, so forgive me if I ask dumb questions

madScientist · « **Reply #237 on:** November 05, 2013, 06:22:04 AM »

Ask away man! I dont believe in dumb questions :-D

Anything I can do to help I will.

SKTP · « **Reply #238 on:** December 12, 2013, 03:32:46 PM »

I just tried to find the info in your thread...but no luck...what is that digital gauge you have there?

madScientist · « **Reply #239 on:** December 13, 2013, 06:01:33 AM »

It's an AEM UEGO wideband to monitor A/F. Welded the sensor into the collector and plugged it in. It's been crucial in getting the carbs setup. It's also really good at indicating when you're running out of gas :-D

http://www.amazon.com/AEM-30-4100-Digital-Wideband-Gauge/dp/B003ITFA9Q/ref=sr_1_2?ie=UTF8&qid=1386943181&sr=8-2&keywords=aem+wideband

sethdhawkins · « **Reply #240 on:** February 04, 2014, 07:36:46 AM »

Chase,

I feel like I've asked you this before. What oil cooler and filter plate are you running? Fittings and line size?

greenjeans · « **Reply #241 on:** February 04, 2014, 09:14:02 AM »

How the heck did I miss this build !? I truly love the builds that showcase individuality, but still are unmistakeable as a Honda.
So clean and nice. That pipe tucks up there much nicer on yours than the photos on CycleXs website - you didn't modify it did you ?
Great job scientist

apetersonboy · « **Reply #242 on:** February 05, 2014, 06:44:00 PM »

Please forgive my lack of correct terminology, but what is the thing that bolts onto the bottom of the battery tray? I can't remember for sure but I think it had a hose going to it from the engine. What does it do, and do you need it? I have a 1978 cb750f too.

madScientist · « **Reply #243 on:** February 09, 2014, 03:02:39 PM »

Seth -- thats an oil cooler adapter from CycleX. I used -10an fittings and stainless braid line. I believe the fittings on the adapter plate are 90 degree NPT to AN and the uppers to the cooler are 45 degree swivel fittings. I'll have to rummage through my receipts to be sure but if memory serves thats what I used. The cooler is an EARL's. I made a cover for cooler weather riding that helps keep the temps up when it's in the 50's here. I was going to put a cutoff in it but just didn't like my routing with it.

Green Jeans -- nope...no modifications to the pipe other than welding in the bung for the wideband. Bolted it on and let 'er rip. That sucker is crazy light too. I was shocked when the box came and i could balance it like a pizza in one hand. Threw the UPS guy for a loop.

Apeterson -- i think you're referring to the condensation catch for the rocker cover hose? If that is what you're mentioning I didn't use mine. I put a filter directly on the rocker cover where the house mounts.

madScientist · « **Reply #244 on:** March 22, 2014, 05:43:08 AM »

I'm starting to understand why Branden called his F "The Annoying Orange"....I'm getting close to calling my "The Belligerent Blue"...

Good news is it runs great. Fired right up from sitting for almost 5 months after fixing a small fuel filter issue. However riding about 50 miles or so I started to notice oil on my pant legs. I have 1900 miles on it and it looks like my head gasket is leaking.

At current I'm not sure where exactly it's leaking but it looks to be concentrated on the front side of the engine...possibly towards the middle. I have had some problems with the cam tower studs so I'm suspecting they might be leaking?

Luckily it's going to be colder this week so I wouldn't have ridden anyway. Therefore I'm going to tear the head out of it and check things over. I know you're not supposed to but I think i'm going to have to helicoil a couple of came tower studs as they seemed kind of loose the last time i checked it over. If memory serves I've coil'd one already. I'm hoping my head isn't warped and that it's either a loose head nut or those cam tower studs leaking.

sethdhawkins · « **Reply #245 on:** March 22, 2014, 06:19:07 AM »

brandEn · « **Reply #246 on:** March 22, 2014, 06:25:34 AM »

Yup. Hang in there. My bike earned its name lol

SOHC4 Cafe Racer Fan · « **Reply #247 on:** March 22, 2014, 07:55:04 AM »

I can relate!

tweakin · « **Reply #248 on:** March 22, 2014, 07:58:38 AM »

Bummer! You will get through this.

madScientist · « **Reply #249 on:** March 22, 2014, 03:42:00 PM »

Thanks guys. It's a tad irritating but I've got too much time, money, and energy wrapped up in this thing for it to not be perfect...well mechanically.

It looks like the oil is head gasket and below. I'm using an MLS gasket. I put it on dry but didn't really do any prep work (aside from decking) for it.

So the game plan is to get the top off, pull head components (checking threads on the posts), check head bolts, double check thrust washer position...if all that is ruled out i'm pulling the head and regrouping to see what I can do to stop the leak...after proving there's no warpage.

Also, what torque do you all use on the head bolts when using an MLS gasket. I used the book values but I think I can go heavier with the HD studs and the gasket.

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Author Topic: 78 CB750F "Modular-ish" cafe build? (Read 59347 times)