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MedicalCowboy
04-29-2015, 7:27 AM
Hey guys I have a 73 CB750. Up until this weekend it's been running great. This weekend after I red-koted my tank it started sputtering and running like total shit at high RPMs. It has pod filters and open exhaust, but like I said it was doing perfect up until this weekend. Any ideas what it could be? Possibly I just picked up some trash and I haven't been able to blow it out with carb cleaner yet. Also, to cut down on all the thread clutter, I'm looking for ideas on a hand shifter. I haven't been able to find a single picture of a foot clutch hand shift set up for the CB750s. So, does anybody have a set up like this and maybe a few pictures? Hell even a jockey shift is acceptable. I just want a damn hand shifter.
Thanks guys.

Jonnycakes
04-29-2015, 7:44 AM
for the sputtering at high rpm.....I'm betting clogged petcock filter/blockage.

Tattooo
04-29-2015, 9:19 AM
How long did you let the red coat dry before you put gas in it???

KeysRyder
04-29-2015, 9:22 AM
High rpms will be your main jets. Does it do it all the time or after riding a bit. if it does it all the time, would say trash in a jet or 2, but if it only does it after riding a bit, would agree with other and say fuel supply issue.

MedicalCowboy
04-29-2015, 10:18 AM
How long did you let the red coat dry before you put gas in it???

I let it cure for over 12 hours before putting gas back in it bud. It idles fine and revs fine at idle, but once it starts to carry a load it starts sputtering. I'll just take the carbs back off and clean them once again. Hopefully that will take care of it.

Tattooo
04-29-2015, 12:05 PM
I let it cure for over 12 hours before putting gas back in it bud. It idles fine and revs fine at idle, but once it starts to carry a load it starts sputtering. I'll just take the carbs back off and clean them once again. Hopefully that will take care of it.

I wish you luck but 12 Hours isn't long enough..... My guess is that it's coming loose and getting in the jets and stopping them up..... Hell after 48 hours it's still soft......

KeysRyder
04-29-2015, 1:15 PM
While on the tank coating topic, anyone ever oven cure? Seems like it may work pretty good.

MedicalCowboy
04-29-2015, 2:38 PM
I wish you luck but 12 Hours isn't long enough..... My guess is that it's coming loose and getting in the jets and stopping them up..... Hell after 48 hours it's still soft......

The instructions stated 8 hours is the appropriate time. There's nothing in my filters or petcocks. The coating was hard hard when I went to put the tank back on the bike.

Tattooo
04-29-2015, 2:40 PM
The instructions stated 8 hours is the appropriate time. There's nothing in my filters or petcocks. The coating was hard hard when I went to put the tank back on the bike.

There must have been something wrong with the stuff I used......... I wonder if you had some trash in the lines before you started??? And then it broke loose?

MedicalCowboy
04-29-2015, 3:49 PM
There must have been something wrong with the stuff I used......... I wonder if you had some trash in the lines before you started??? And then it broke loose?

I just let mine set up for a few hours then I let a fan blow through it for the rest of the night. Yeah, I just need to quit being a lazy ass and when I get off take the carbs off and clean them. So, any hand shift ideas? Lol

MedicalCowboy
05-03-2015, 8:50 AM
Well it's definitely not the carbs. I'm going through and looking at the points system today. Any pointers?

Tattooo
05-03-2015, 9:19 AM
Well it's definitely not the carbs. I'm going through and looking at the points system today. Any pointers?


Could you have pinched a wire when you were working on it?

MedicalCowboy
05-03-2015, 11:59 AM
Could you have pinched a wire when you were working on it?

I've removed the tank about 7,381 times in the past week so there's a good chance. I'll check it out. I appreciate the help bud.

MedicalCowboy
05-03-2015, 7:01 PM
Well everything was cleaned and looked at today. My plugs were BLACK and that happened in about 3 days of riding. I need to borrow a timing light so I can officially check the points and timing. But it's not the carbs, and all the wiring is the exact same as it's been. So that leaves points and timing. It's just odd that it cranks fine, idles decent, and runs like total shit under load.

mantree
05-10-2015, 2:51 PM
i had the same problem on my vt1100 turns out that i had gotten crud in the pickup line on my petcock and eventual the screen became so clogged it wouldn't even let fuel flow at all. it happened about 5 times in 6 months before i just gutted the screens out and replaced the inline fuel filter ever month or so (bought a box of 100 for 20 bucks from a shop that was closing)

mantree
05-10-2015, 2:57 PM
Well everything was cleaned and looked at today. My plugs were BLACK and that happened in about 3 days of riding. I need to borrow a timing light so I can officially check the points and timing. But it's not the carbs, and all the wiring is the exact same as it's been. So that leaves points and timing. It's just odd that it cranks fine, idles decent, and runs like total shit under load.

you may have a air restriction

MedicalCowboy
05-11-2015, 1:14 PM
It turned out to be a bad condenser. Replaced both condensers, checked the points, and she's running like she use to.
Thanks for the help guys.