Backfiring into carbs

[BurnsYoFace34]

Hey yall its been awhile since ive been on here. Ive got a 77 gl1000 ive rebuilt the carbs with randakks kit. New everything. Ive had them off the bike because i was going to put a 2barrel 32 weber on it. I cant get the weber and all that to line up right. So back to the og carbs. Put them on and fuel is leaking into the plenum. Took them off found that an i let port was blocked up. But still getting fuel into plenum. And when i try to start it. It fires but back up through the carbs. Would this be a float issues. And any other advice qould be great thanks

[gltriker]

Hey yall its been awhile since ive been on here. Ive got a 77 gl1000 ive rebuilt the carbs with randakks kit. New everything. Ive had them off the bike because i was going to put a 2barrel 32 weber on it. I cant get the weber and all that to line up right. So back to the og carbs. Put them on and fuel is leaking into the plenum. Took them off found that an i let port was blocked up. But still getting fuel into plenum. And when i try to start it. It fires but back up through the carbs. Would this be a float issues. And any other advice qould be great thanks

Start over

[BurnsYoFace34]

20250603_181145.jpg

Right. Lol. So upon taken the bowls off i found 2 bolts on cyl4 bowl the threads are stripped causing a leak. And 2 of the small jets that im pointing at 2 rubber gaskets were smashed and missing

[robin1731]

Thought you just rebuilt those?

[BurnsYoFace34]

Like a yr ago is when i did. Then i wanted to single carb it so ive been back an forth with single carb oem carbs. Idk what i wanna do with it. I just want to get it on the road an ride

[redglbx]

Couple of my thoughts….

The good thing about the single carb Weber setup is that there’s no more need to balance the carbs and there’s only 1 carb to deal with.

The bad:
Performance wise the factory oe carb setup will flat-out wipe the floor with the the Weber , the Weber will have better initial throttle response due to its mechanical link & accelerator pump vs the factory vacuum linkage & no accelerator pump (1000 carbs) but a well setup set of oe carbs can be really responsive.

It’s funny to say but parts are easier to get for the oe carbs than the Weber and finally a lot of the single carb performance/issues can be linked to the intake.

As you can probably tell, I’m not a fan of the single carb setups, you just give up too much performance with it and quite frankly if the oe carbs are setup well they don’t give up anything and can just run great for many years, yes they can be a little finicky, maybe but there’s 4 of them,,,, I have yet to see a single carb setup where I didn’t come away feeling like the linkage setup wasn’t just a rinky-dink deal.

Anyway that’s my opinion on the oe vs single carb setups ,, I have had a fair amount of time with both either setting them up or riding them and as I said I’m really not a fan of the single carb setups.

[BurnsYoFace34]

I agree with your opinion. Id rather have the 4 oe carbs. But for some reason i havent been able to them in tune to either not leak or its always something with those carbs. And i cant figure it out. Just trying to find an easier bolt on to get it running so i can finally ride this beast

[Old Fogey]

Perhaps you should ship them to Robin for a proper rebuild. O rings don't just get smashed up and missing by themselves.

[redglbx]

[BurnsYoFace34]

I should. Then they would be done rite. How much you charge robin?

[BurnsYoFace34]

So update. Took carbs off and was cranking it ober right. I just happened to look down into cyl. 2 intake and see that its not fully closing. Smh. That explains everything. Guess im doin a head job again

[redglbx]

Bent valve ? Did you break a cam belt at some point ? Over rev’d the engine ? Once you get the head off , set it up on your bench with the combustion chambers up and leveled, pour a little water or fuel into the the combustion chambers, if it leaks into the ports you either have a bent valve, damaged seat or valve face or seat or possibily a sticky/dragging valve guide.

Either way, you have some work in front of you. The good thing is that none of it is terribly hard just a matter of time. Let us know…

[BurnsYoFace34]

Um at one point i did have a cam get snagged up and like kinda looks like a small peice of metal got between the camshaft and the cam nearing causing it to stop. So it snapped the cog side of the cam and timing belt off. But that was cyl 1/3 side. The bent valve is opposite. Cyl 2/4 side

[redglbx]

Have you rechecked your cam timing marks since your event and were they off ? Have you checked your compression since ?

Honda builds zero clearance motors, they will tolerate maybe 1 tooth off on the cam timing but more than that and Mr piston will get personal with Mr valves. At this point I’d be pulling both heads and checking things, again, set the heads with the chambers up and level, pore some fuel/water into the cylinders and see if anything leaks past the valves and into the ports,, it shouldn’t have any ! Also keep in mind that you can dress/gring the seats but NOT the valves themselves.