Suoer G spiting

[tatajoe]

Good dsy brothers. I recently did a 585 cam swap. Everything else is stock. Motor starts but starts spitting out the carb, out the pipes, 2 into 1 Vance hines and smell like raw fuel. Where do I start. I did a carb rebuild (stock) a while back but now this. Ideas pleezz post script...was running good after card rebuild.

 

[tatajoe]

Spark plugs come out with soot (black) and she doesn't like to be choked at all

 

[HMAN]

You may have to rejet the carb. Or maybe you have a stuck float? Drop the bowl n give it a look see. Sure sounds like its rich but with a cam swap I could see jetting higher? Keep us posted. Pic dont hurt either.

 

[Snuffy]

You may have to rejet the carb. Or maybe you have a stuck float? Drop the bowl n give it a look see. Sure sounds like its rich but with a cam swap I could see jetting higher? Keep us posted. Pic dont hurt either.

Yeah what he said. I would think that a cam swap would make it run lean it appears to be rich. Sounds like a stuck float

 

[Mickmorris]

Spark plugs come out with soot (black) and she doesn't like to be choked at all

Running rich. Need to adjust the fuel/air mixture screw in until it seats lightly then back it out 2 1/4 turns. Start there and get the bike to idle. Then you can fine tune the fuel/air mixture.

 

[tatajoe]

Awesome, on it now. Will let you all lnow

 

[Mikeinjersey]

Good dsy brothers. I recently did a 585 cam swap. Everything else is stock. Motor starts but starts spitting out the carb, out the pipes, 2 into 1 Vance hines and smell like raw fuel. Where do I start. I did a carb rebuild (stock) a while back but now this. Ideas pleezz post script...was running good after card rebuild.

Your description is a little unclear. It sounds like after the carb rebuild you had no problems. Did the problem happen immediately after the cam change or did it actually run and then fail days later? IF all was well before the cam change it would be quite a confidence that the float would start to stick . Is any fuel coming out of the overflow? These files will help you dial in the carb.
Someone with more expertise than myself might know if cam timing could cause this symptom ?

 

[tatajoe]

Thank you, it ran good after the cam swap. I tried , twice, to adjust the float. She still pops alot and at the start she pops like a shot gun going off. I'm at my wits end here. Gonna study up on the info you sent. Thanks again mikeinjersey.

 

[bikeone]

Maybe the 585 cam change makes in case of charge change another main jet necessary?
I did only a cam change on ohc engine and switched to open air intake so I am not sure.
stage two cam from Pops Yoshimura, valve springs from mitchell/ CA were my base.
in this case were bigger main jets necessary.
only my thought.

 

[HMAN]

Thank you, it ran good after the cam swap. I tried , twice, to adjust the float. She still pops alot and at the start she pops like a shot gun going off. I'm at my wits end here. Gonna study up on the info you sent. Thanks again mikeinjersey.

Check the black rubber caps on top of the carb. If you see any cracks while pushing on them, replace em.

 

[john sachs]

Good dsy brothers. I recently did a 585 cam swap. Everything else is stock. Motor starts but starts spitting out the carb, out the pipes, 2 into 1 Vance hines and smell like raw fuel. Where do I start. I did a carb rebuild (stock) a while back but now this. Ideas pleezz post script...was running good after card rebuild.

Sounds like your CAM Timing might be off a tooth, or a possible valve adjustment issue.
John

 

[Mikeinjersey]

Thank you, it ran good after the cam swap. I tried , twice, to adjust the float. She still pops alot and at the start she pops like a shot gun going off. I'm at my wits end here. Gonna study up on the info you sent. Thanks again mikeinjersey.

Just a thought. You are experiencing fuel spitting and the bike doesn't like to be choked. The Super G carb has an enricher not a choke. Is it possible that when you rebuilt the Carb you didn't put the enricher valve back correctly and now its flooding out the engine?

 

[Rottweiler]

So you rebuilt the carb first and bike ran good. Then you put in the cam and bike ran good? If this is true I agree with Hman replace those rubber caps.

 

[tatajoe]

Brothers, all your inputs make sense, I now remember that I installed a Thunder Heart ignition and never used the cd and cables that came with it and mikeinjersey, Mr. Sachs and hman, yohuman, made a lot of sense as well. I'm at my wits end with this. I removed the bowl three times now, adjusting the float and still same results. I'm afraid of detonation at every start. So I'm gonna take each one of you alls advice, order a new rebuild kit, tune that thundeheart and I'll let you all know what's happened. Thank you all and have a great and safe Thanksgiving

 

[tatajoe]

Well, Im back at it with the 06 Mastiff, so todsy I performed a compression test on both jugs, front one gave 100 and the rear gave a reading of 110. I think that's not good at all. Could I have bad valves, the compression tester holds on those numbers until I press the release button. What's the real bad new for me brother or which way should I go. Thank you all

 

[Sven]

You're SOL tatajoe. Most shop manuals show a range of 150 pee yes I said it's rebuild time 40 pounds ago. That's from the old Hondas from the '70, to 153 for one of today's world's fastest. That's minimum pounds or out of range is 149 psi. Ducati's manual shows capital POOR next to 150.

Say you see a range of 153 to 187. Add both, divide by 2, there is your blueprint running compression of 170 psi.

You are missing a lot of kinetic to help light off the gas. Thus the rich condition. Carb wise, I'd run the screw in or out, meaning, screw is on the air cleaner side, it's for air. Screw on the head side, it's gas. Needs all 3 jets to start engine. Unless you take off with the rich lever on to start, push off when running in gear. Stop at a light, it's going to take a screw at some sweet spot to idle.

But that's a band=aid fix because you are flat out of spec. You'll have more hair, less stomach problems, accept what the book's abstract says or how to read the high/low. I'd stop tuning it.

The question is: Does this bike start right up? If yes, it's not out of mechanical time. Fix the top end first.

 

[Mikeinjersey]

Well, Im back at it with the 06 Mastiff, so todsy I performed a compression test on both jugs, front one gave 100 and the rear gave a reading of 110. I think that's not good at all. Could I have bad valves, the compression tester holds on those numbers until I press the release button. What's the real bad new for me brother or which way should I go. Thank you all

It is normal for the tester to hold the highest pressure reading until it is released. Your pressure is low ( if you read it correctly) but your symptoms don't add up to that being your problem.
It is unclear to me when your problems started.
Did the bike ever run well after you rebuilt the carb? If no pull it apart again. If the answer is yes then, Did the problem start after the cam change ? It's important to know in order to have a better idea of where your problem is most likely to be. If the problem started right after the cam change that's your answer.
My 2 cents : I'm sticking with the carburetor causing your spitting. Low compression or bad timing could definitely cause your engine to run poorly or not at all but less likely to cause raw fuel to dump out of your carb and exhaust.

 

[tatajoe]

Back tracking to when I first got this Dog, it would back firing like a shotgun when it started. I thought it needed a top end overhaul so I installed new jugs with standard pistons/rings. I didn't rebuild or did anything to the heads or valve train. it did start right off and ran but noticed that it was running a little rich. I then thought and did a cam swap and again it started right up but still hd that miss or rich fuel smell. Rebuilt the carb and it still runs rich, I then decided to check the compression and seen the low numbers. I rebuild and customize V8's and I now realize that motorcycles are very different. I took extreme measures for being hard headed. so after all that I have done, would I be headed in the right direction by having the heads redone? I'm learning with you all and so I do thank each one of you.

 

[Mikeinjersey]

What size jets do you have ? Check for vacuum leaks first then go through the adj procedure. Keep in mind the idle mixture screw and idle speed screws are not the same. One sets idle speed rpm and the other adjusts the amount of fuel. Read the idle circuit notes in this file, it will give you some insight as to where the adjustment should be.
https://www.bigdogbiker.com/attachments/s-s-carb-tuning-tips-pdf.130134/

I would say your headed in the wrong direction but if you do want the heads done contact john sachs from post #11 to have him do them for you.