Topic: Colorado 750 K5

[750K5]

Zach,Those caliper parts look as new.Did you build that front wheel with a new rim and spokes ? 

Thanks,
I did install new wheels.  I used cost effective spokes hopefully they will last.  I don't plan on riding in inclement weather.

[750K5]

I rode the bike today for the first time.  I think jetting is in order.  Does anyone have thoughts on 4 into 1 exhaust and jetting adjustment? Stutter at RPM above 4500. Runs smooth in all other ranges.

[grcamna2]

Sounds like a rich transition between mains and needles.

[DennyK]

Greetings from smoky Grand Junction.  Great Job!  I restored a 74 750 a few years ago.  Sold it in a moment of weakness.  Restoring that bike was one of the best experiences of my life.  Met some great folks along the way and this Forum plus Mark's book were essential resources.  Mine ran okay, but I never got the carbs synced.  Don't be stupid like me; keep that thing!

[BenelliSEI]

Been catching up a n the last few pages. Great job, bike looks great! Well done!

P.S. if you need a cheap IV tank, just pick up the biggest Turkey Baster you can find at WalMart! Pull off the bulb, add a hook and push on a hose. I have one that holds about a cup of fuel and works well enough......

[750K5]

Been catching up a n the last few pages. Great job, bike looks great! Well done!

P.S. if you need a cheap IV tank, just pick up the biggest Turkey Baster you can find at WalMart! Pull off the bulb, add a hook and push on a hose. I have one that holds about a cup of fuel and works well enough......

Thanks for the IV advice. I just ordered sync gauges so I'm going to need to plan my auxiliary fuel supply for tuning. I'm looking forward to the carbs being dialed.

[750K5]

Greetings from smoky Grand Junction.  Great Job!  I restored a 74 750 a few years ago.  Sold it in a moment of weakness.  Restoring that bike was one of the best experiences of my life.  Met some great folks along the way and this Forum plus Mark's book were essential resources.  Mine ran okay, but I never got the carbs synced.  Don't be stupid like me; keep that thing!

Thanks for checking out the build. I have learned a ton here and was fortunate to meet Mark. I live near him and he overhauled my swingarm bushings. I have enjoyed the process so much I have another basket case in the shed . That bike is a seized 71' engine w a titled 76' frame. I imagine when I get to it I wont feel bad doing some modifications because it's a Frankenstein bike. The Colorado smoke is burning me out.. I hope you are staying well being that close to the fires.
K5

[750K5]

Sounds like a rich transition between mains and needles.

So do you suggest I lean it a bit?

[grcamna2]

Sounds like a rich transition between mains and needles.

So do you suggest I lean it a bit?

Yes,What size main jets are you running now and what air filter are you running Zach ?

[750K5]

Sounds like a rich transition between mains and needles.

So do you suggest I lean it a bit?

Yes,What size main jets are you running now and what air filter are you running Zach ?

Stock... 40 pilot.. 105 main... stock basic filter.

[grcamna2]

I want to say up front that I don't know how to adjust the needles in 'Round Top' CB750 carbs,but that's what you might do:lower all the needles one clip position,in other words with the needles pointing down,bring the clip Up one position.

[750K5]

I spent the last couple of days tuning.. unbelievable how much timing and sync smooths everything out!
I feel that I'm as close to dialed as I can get it.  It would be nice to find another SOHC 750 in Colorado to listen and compare.  I guess aside from paint she's road worthy.  I'm going to schedule a vin inspection next week and get title and insurance taken care of.  Now hopefully the smoke will clear and the temps will cool for some fall riding. 

[750K5]

The bench sync was pretty close.. static timing was a bit off. It started purring after we got the timing light involved. (Thanks Scott!)
I also made an aux tank for those who were kind enough to pre warn me about using the tank..

[SOHC4 Cafe Racer Fan]

Clean-looking bike.  Are you pretty much done or are you also adding sidecovers?

[750K5]

Clean-looking bike.  Are you pretty much done or are you also adding sidecovers?

Thanks for checking it out. I have new side covers and emblems on the bench.  I'm planning to paint them this weekend.  The plan is to paint the tank this fall. I also have some other odds and ends.  Restore gauges and headlight. I'm also planning to replace the shocks. I decided to assemble what I had so I could ride some this season!

[HondaMan]

Yeah, the biggest ride-time is just now upon us Coloradans! Most of the tourists are thinning out, traffic dropping down, still dry for the next 2-3 months. Good time to hit the high country! Thinking of going up Evans next weekend on mine. Bummer it costs $5 now, used to be free.

[Jerry Rxman Griffin aka MuthaF'er]

Mark, are you paying the Feds fee or is the state now charging? Used to be you'd tell the feds you are heading to the top and you didn't get charged??

[HondaMan]

Mark, are you paying the Feds fee or is the state now charging? Used to be you'd tell the feds you are heading to the top and you didn't get charged??

My last ride up to there was last summer in July (4th). I asked at the time if the top was open and they said 'yes', and then said, "that will be $5". I don't know if that was for the information, or the admittance. On the way up I met 3 grouchy riders on new BMWs coming down (only 2 spoke English, they were Germans, which I can still understand a little). They were #$%*IN' that the "weather at the upper part of this road is terrible" and that they thought they should get a refund since they didn't make it to the top due to snow and sleet. Then they asked if I was "planning to ride that old Honda to the top, you probably will not make it", to which I replied (with a smile) that I do it every Summer, either on July 4th to celebrate America's birthday, or on Labor Day to celebrate taking a day off. The 2 who understood English both said, "On THAT?"

Then I smiled and rode on up.

[Stev-o]

Mark, are you paying the Feds fee or is the state now charging? Used to be you'd tell the feds you are heading to the top and you didn't get charged??

On the way up I met 3 grouchy riders on new BMWs coming down (only 2 spoke English, they were Germans, which I can still understand a little). They were #$%*IN' that the "weather at the upper part of this road is terrible" and that they thought they should get a refund since they didn't make it to the top due to snow and sleet. Then they asked if I was "planning to ride that old Honda to the top, you probably will not make it", to which I replied (with a smile) that I do it every Summer, either on July 4th to celebrate America's birthday, or on Labor Day to celebrate taking a day off. The 2 who understood English both said, "On THAT?"

Then I smiled and rode on up.

Good story HM!

[PeWe]

Found the proper jetting of the carbs?
My K2 with K6 carbs, stock airbox, rather good flowing Yamiya No numbers 4-4 ( like HM300.)
- Air screws 1 turn out from bottom
- Pilot 40 (stock)
- Needle at 4th notch from top
- Main 115

I have tried needles at 3rd notch and 105 mains (as my K6 had as stock with bad flowing HM341 4-4)
Increased main to 110, 115 and finally 120 where middle range woke up (most fun here), but too rich att full.

That made me to understand that needles must be raised and slightly smaller main jets.

It depends on your exhaust if it flows well or is restrictive.

My 4-4 have baffles (diffusers) in but no wool.
56whp on dyno. No A/F checked since baffle must be off. Bike feels OK from idle to full as the Dyno guy also noticed.

I had a small hesitation when taking off, drilled the smallest pair of holes in the emulsion tubes with 1mm drill, better.

[HondaMan]

At this altitude, the air screws should be between 3/4 and 7/8 turn out from the inward stops, and the mainjet for the K4-6 should be #105. Needles should be in 4th notch from the top. Spark advance should be dead-on "F" for both sides, but I do recommend stiffer advancer springs (I cut off 1 full coil on one side and 1.5 coils on the other on my AD125 Hitachi advancer, while 1 turn from 1 and 1/2 turn from the other should be about right for the K4-6 TEC advancers). The plugs: I use mostly X24ES-U or XR24ES-U with regular gas in town or mid-grade fuel for the high country (mostly above 4500 RPM), and premium out east beyond Burlington (3500 feet high)

[750K5]

At this altitude, the air screws should be between 3/4 and 7/8 turn out from the inward stops, and the mainjet for the K4-6 should be #105. Needles should be in 4th notch from the top. Spark advance should be dead-on "F" for both sides, but I do recommend stiffer advancer springs (I cut off 1 full coil on one side and 1.5 coils on the other on my AD125 Hitachi advancer, while 1 turn from 1 and 1/2 turn from the other should be about right for the K4-6 TEC advancers). The plugs: I use mostly X24ES-U or XR24ES-U with regular gas in town or mid-grade fuel for the high country (mostly above 4500 RPM), and premium out east beyond Burlington (3500 feet high)

Thank you !
Its currently running great. I'll be referring to this post as I continue to tweak and tune.

[750K5]

I finally found some time to paint the side covers. A flaw here and there but I'm overall happy w the results. I think a little wet sanding and polishing things should look pretty sharp. The fuel tank looks pretty faded compared. I'll be looking into the bodywork and painting that ASAP.

[gpzkat]

Looks great and I really like the color.  Did you use spray cans for the final coat?  Wet sand and polish works miracles in my experience.

I'm thinking about trying to do my own paint on my  '73, sunrise orange flake is the color I like best but it's almost too common, which I understand because it looks so good.  I'm not sure of my skills, transitioning from cans to 'real' painting and getting all the proper equipment.  I have done tanks with spray cans that came out great, in fact I placed at a show with a two-tone with stripe on an old Triumph Bonneville - nobody could tell.  But I still remain a bit doubtful with all the setup and mixing etc. for painting with compressor and gun.  And learning on such a complex process like the Honda tank isn't the easiest intro.

I finally found some time to paint the side covers. A flaw here and there but I'm overall happy w the results. I think a little wet sanding and polishing things should look pretty sharp. The fuel tank looks pretty faded compared. I'll be looking into the bodywork and painting that ASAP.

[750K5]

Looks great and I really like the color.  Did you use spray cans for the final coat?  Wet sand and polish works miracles in my experience.

I'm thinking about trying to do my own paint on my  '73, sunrise orange flake is the color I like best but it's almost too common, which I understand because it looks so good.  I'm not sure of my skills, transitioning from cans to 'real' painting and getting all the proper equipment.  I have done tanks with spray cans that came out great, in fact I placed at a show with a two-tone with stripe on an old Triumph Bonneville - nobody could tell.  But I still remain a bit doubtful with all the setup and mixing etc. for painting with compressor and gun.  And learning on such a complex process like the Honda tank isn't the easiest intro.

I finally found some time to paint the side covers. A flaw here and there but I'm overall happy w the results. I think a little wet sanding and polishing things should look pretty sharp. The fuel tank looks pretty faded compared. I'll be looking into the bodywork and painting that ASAP.

I wrote this on another thread for someone who inquired about the process I used. I have painted wi a gun and chose this way because his OMF bike turned out so nice!

I scuffed covers w scotchbrite wet. Dried and cleaned w alcohol. Most suggest grease & wax cleaner. I didn't have any. Next I used adhesion promoter 2 light coats 10 min apart. Then 3 light coats primer 10 min apart. Once the primer dried I wet sanded surface w 1500 until smooth. Next applied color match from VMR paints (they seem to be able to match closely most vintage honda colors). 3 - 4 coats 10 min apart. Finally 4-5 coats 2k clear coat. Allow time to kick, I would wait 20 min between coats Depending on ambient temperature. If like me no access to a booth clean your area and wet floor and set a an exhaust fan. Once you lay the clear coat put a plastic storage tote over parts to cover and act as a minnie booth so debris wont find your part. These are rattle can products. I met a guy at a show w some of the most beautiful hondas I've seen using the same process and products. Hope this helps. I started w the covers for practice I'm still building courage to do the tank.