sdhawkrider

Some backgound, It's a 2002. What led up to this point is I replaced the front head. The bike was fine prior to CCT failure. So I got a used head, checked the valaves, installed the head. Everything was all back together and I fired it up. Bike runs just fine at idle, and starts up with ease. Let it thoroughly warm up and twist the throttle, The bike revs to almost 3000 RPM, lugs out and nearly dies.

Again, this was a running working bike 3 weeks ago. No carb issues, nothing. So I am having a hard time believing that the carbs need cleaning. Would they need to be synced since it is a different head?

I have pulled the tank several times trying to track down a missing vacuum line, and I believe all is well. There is fuel in the lines from the tank to the carbs.

Any suggestions on other things to look for? Any tests that I can perform?

RWhisen

PVLIR.

sdhawkrider

Vacuum line is attached to the back of the petcock, not the vent on the bottom.

RWhisen

Does fuel deliver to both carb lines when you suck on the vacuum line? Sure sounds like a vacuum leak.

nath981

did you verify timing marks are correct for front and rear; set tps; sync carbs(is there a boost joint on the rear carb for syncing); is it running out of fuel(i.e., if you let it idle as if you were syncing the carbs, will it run out of fuel) or does it quit onlywhen reved?, diaphragm in the petcock broken?

and you might gets some ideas from this thread:

https://www.superhawkforum.com/forum...-issues-29191/

Renderw

Too funny I just posted the identical sysmptoms a few days back.. so I'll update you on where I am.. I couldn't get it to rev past about 4500 and its smoking really bad, pulled the valve covers off today and found the rear cam on the front head was out 1 tooth. seems my manual CCT's were not tight enough.. I think I got off lucky.. not back together yet need to mod my CCT's so I have more adjust ment.. but based on my experience check your timing

sdhawkrider

I will double check the timing but I am doubting that is the problem. I did hook the TPS back up but did not do the modThere is a boost joint between the carbs, should that be capped? When the bike is at idle, it will idle all day long. It only quits when revved.

nath981

the boost joint on the front carb should be capped until you sync the carbs. We usually have tubing running over to the left side of the bike where it is capped so that it will be handy for syncing. So since you read the thread, i suppose you checked the air screw, slides, jets and airbox,etc. It does sound like you could be running out of fuel since it happens when reving, not idling, if the floats are not supplying enough gas to keep up with higher rpms or have a faulty diaphragm.

These engines are so finicky that if one thing is off, it raises hell(spitting coughin, backfiring) like it's getting ready to blow.

sdhawkrider

Well the problem is solved! Problem was a missing vacuum line that connects to the front head. The used head I received had the connection plugged. I looked at my broken head and saw a connector for a vac line. Swapped the two out, ran the vac line and PRESTO! Bike fired up and revs. Just got back from a test ride and all was well, except for the bike nearly overheating. Thanks everyone for the help and ideas!

nath981

well that's wonderful except for the almost overheating huh.

Renderw

That's great!! now I have a questions.. what line is that? there are two lines coming off the valve covers, large tube and smaller one with a read valve.. my read valves are blocked by TBR blocker plates and I have two brother pipes.. I assume the last guy new what he was doing when he did this? does anyone else have this setup?

sdhawkrider

The line I am talking about is a small vac line that attached to a port on the front head, about 5 oclock from the front carb intake boots. The other end attaches to a boost port on a plastic gizmo that is attached and in between the two carbs. Sorry, I don't know the technical terms.

Also, my over heating is my fault. Test ride was done with only half the coolant required. Luckily I got home right before the the blinking temp gauge indicated way too hot!

E.Marquez

Pictures please

sdhawkrider

This is a pic looking down at the carbs, the right is facing the front of the bike.This is where the vac line attaches at this end. The other end attaches on the head.

Tweety

That would be the vac line that opens the petcock, ie vaccum operated fuelvalve... It's not very surprising that it's needed, really... I was mentioned in the very first reply to your post... And no, it wasn't magically disconnected between then and now, you disconnected it, on purpose or by mistake and failed to note where it should be connected...

Lesson one in learning to work on your bike... No, you are NOT going to remember where everything goes... Not now, not the next ten times... So you can either use paper and pen, or a digital camera or some other way, and document the stuff you take apart... Or end up confused by you own doing... Simple choice, even simpler answer...

Hawkrider

Okay, let's get this cleared up:

On NON-CA emissions bikes there is nothing on the front head intake except for an allen bolt and a seal washer. This port is used for syncing the carbs ONLY. If there is a nipple there then this is either a CA bike or the PO bought one, used it for syncing the carbs and capped it, or left the tube on there (and hopefully plugged it).

On CA emissions bikes there IS a port/nipple coming off the front head and that gets connected to the carburetor air vent control valve. That is what that picture is above. If the CA emissions has been removed then there should either be a cap on the port or a hose attached with a plug at the other end.

On ALL bikes, the same mirror image port on the REAR head goes to the vacuum operated petcock on the bottom of the tank. The correct nipple on which to attach that hose is located on the REAR of the petcock, NOT the bottom, and is difficult to see without looking for it.

Please see my website for directions on removing CA emissions, PAIR, carb removal and setup, and carb syncing. Also, please refer to the Honda Service Manual, page 1-26 for CA bike hose routing.