What am I missing

[Suzuki mad]

Stripped and cleaned the carbs of my GS1000ET (CV) and found a blocked pilot jet and loads of rust from the tank after a fuel sway to change the fuel tap. I haven't cleaned them completely and changed the 'O' rings as per the carb papers. The bike started and rans OK but has now developed a little hesitation.

Ran it today and found that 1,3 and 4 pipes got very hot (cherry red!!) yet No 2 was normal colour.

So its check that No2 is getting spark (swap 2 and 3 leads)
Check No2 carb is clean.

And what else.

Suzuki mad

[Zook]

If the pipes are cherry red they are VERY VERY lean. The cylinders with red pipes probably have junk in the carbs and/or air leaks.
#2 is probably normal.
Clean the tank and intstall a filter.

Did you check the mixture screws?

[lee1rbc]

same thing with my bike, I had just finished dipping my carbs and cleaning out the tank and still wasn't running right. Hard to start when cold, sputtered and popped.

Took the temp reading of each header by the head #1 = 230F #2 = 400F #3 = 520F #4 = 700F. Pulled the plugs and 2,3,4 looked OK but #1 was rich.

I synched the carbs this morning and that solved the problem. #4 was pulling a little more then #3 and #2 was pulling more then #1. 3,4 were pulling a little more then 1,2.

Took temp reading after a nice 20 mile ride #1 = 540F #2 = 510F #3 = 510F #4 = 510F. Pulled the plugs and they are all brown perfectly clean, I might turn the idle screws out a 1/4 turn.

[76FJ55]

could verywell be sync and idle screw but if you petcock diaphram is leaking it can dump unmetered fuel into the #2 intake through the vacuum line. This would also cause you to drop the second cylinder.

[Suzuki mad]

Swapped leads 2 and 3, made no difference. I haven't synced the carbs (don't have the tools[will be on order Monday]) so will give that a go. If not then its got to be carbs back out and do the job again. This time with new 'O' rings. NO, I didn't remove the mixture screws and my fuel tap is brand new (third new NOS vacuum tap.)

I might get a pingle but it doesn't keep with the originality of the bike.

Pipes only go cherry red as I was giving a load of rev's (6,000-7,500) and its a motad pipe.

Suzuki mad.

[seuadr]

what about you carb boot o-rings? taking the carbs off and on last time could have bee nthe last straw for'em.

[Suzuki mad]

No nearer an answer.

what about you carb boot o-rings? taking the carbs off and on last time could have bee nthe last straw for'em.

New ones fitted this time round. (Had to have two screws drilled out)

Chatted with a mate at work today who suggested that the airscrews, which I haven't changed may be the problem as with the junk in the carbs the PO may have played to get it running.

Suzuki mad

[seuadr]

could be, sounds like a definitally lean condition.. but it could also be the carb sync. i forget, did you bench sync'em?

[Steve]

Ran it today and found that 1,3 and 4 pipes got very hot (cherry red!!) yet No 2 was normal colour.

All good points above, and I don't really have anything to add, but are you sure they got cherry red?

This is what my son's bike looked like when I was trying to check stator voltages:


We have since gotten the bike running quite well, but the carbs need to be tuned a bit more. That will happen after I replace the stator, so I can go out on test rides without draining the battery.

Not sure which part of the repair process 'fixed' the red-pipe issue, but we replaced the head, checked the rings, honed the cylinders and cleaned the carbs. It now starts very easily, but stumbles a bit when given a bit of throttle on the road. Plug chops are in the immediate future, as soon as I get three other short-term projects off my bench.

.

[Suzuki mad]

A lot redder than that but your on the right line for all but No2.

Well I am guessing that I must have done something wrong with the carb clean (newby mistake) so I will try the air screws and then its strip them off and do it fully as per the papers with new 'O' rings.

Cheers guy's,

Suzuki mad

[Suzuki mad]

Went out to the garage tonight and thought I run her on prime to see if the fuel tap is duff (again.) Turned the slot to prime and started her up and she ran really lumpy. As I looked down I could little spits of fuel coming from the top of the carb so I put my hand down to check the caps to see fuel pouring down the carbs and onto the running engine.

Stopped the bike, took the tank off to find as split fuel pipe.......

Cut the damaged end of the pipe off and refitted. Started her up and away she ran without problems. No lumps no red pipes no nothing. Could a splitting fuel pipe be allowing that much air in to stop fuel getting down the line to the carbs.

So looks like my bikes running again. Thanks guy's.

So, just as a suggestion, that added to the carbs strip and rebuild is inlet and vacuum pipes.

Suzuki mad

[doctorgonzo]

Good one.
I had a lean carb #2 once from having 3/8 fuel line on the vacuum instead of 1/4 vacuum hose. Enough vacuum to open petcock, but leaky enough to lean out #2.