RPM hang up ?

[oseaghdha]

I see you sprayed the boots looking for a vac leak, but did you try to spray the throttle shafts at the seals?

[Guest]

carbs

hey tc i don't know the jet size po said all stock ,floats are 23mm, using a motion pro sync. and i don't remove the vac adv hose from2 carb, i also tried richen it up by 1/2 turn seamed to at 1st run better but only got worse as it warmed up. the plugs are all tan ,it doesn't have that crisp crack when i hit the throttle
OSE. i didn't try throttle shafts i have a feeling i'll be pulling the carbs and going through them again ,that's what it took on my 78 and it's running great it's the best way to learn practice makes perfect!
thanks

[Guest]

Rpm hang up!!!!!!!!!still

well guys pulled the carbs recheck & cleaned after i bought a magnifying glass found mains were 110 across so i put it back stock 120's on 2&3 i have 42.5 pilots an idle mix 1 1/2 out timing is right on, slides were all wooshing but this time i check the diaphragms with a mag light behind them and found 2 tiny pin holes in carb 1 it changed it out thinking this is the problem nope still doesn't have crisp rev when you hit the throttle & the rpms still slow to come down,also pulled vac adv line from carb 2 had no effect any other ideas out there sure could use the help I'am stumped on this one

[John]

You might try turning the pilot screws out some more. Montreaux Blue and I just went through his carbs, and he was having similiar problems. Turned the pilots out to about 5 turns, and the problem was fixed. I know 5 turns is a lot, but he has pod filters, and the stock exhaust. It seems he needs to increase the pilot jets by one size, and turn the screws back in a few turns. He was running way too lean on the pilots. The pilot circuit is in play at all throttle openings.
Also, did you check the cable adjustment, the silver 90 degree bend where the cable enters the switch housing. That may need tweaking.

[Guest]

Hang up

hey john well went out there this morning put the pilots out 5 turns and adjusted cable slack must really be stretch I'm at the end of the adjustment fired her up and same thing no crisp throttle and comes down slow! now when i replaced the diaphragm i noticed no small washer between the needle and spring on the new part does that washer lean or richen the carbs? I'm starting to think about putting my carbs from my 78 which i know are right, will they work on this 81 sh ?

[DGXSER]

For the 81 carbs, that washer would go on beofre the spring, so only increase the spring pressure on the needle which could maybe lean it out a bit.

The 78 carbs should work fine on the SH. Be aware that you will not have anyplace to hook the vent lines from the top of the carbs to though, leave them open to air. The plugs on the air box are not open. HTH

[John]

You can easily run a drill through the blocked nipples on the air box. I have 78 carbs on my 80SG, and that is what I did. The washer on the pilot screw acts like a spring seat, so the spring doesn't chew up the O ring.

[Guest]

Still

ok i put my 78 carbs on the 81 just to maybe eliminate the carbs as the problem it did the same thing!so i'm back to vac leak i have new boots on when i received them they came with gaskets thought maybe they were not built well? read debeardsle post when he took his boots off the gaskets were wet mine too the only place the gaskets stuck to any surface was on the bolt ears [leak in the center?] looked at the boots closer there is a raised center i put a straight edge across it and it's higher than the ears left gaskets off the raised center [ rubber ] sealed up nice on that polished surface but still not running right! went back spraying for leaks boots none throttle bar none and the one i didn't check choke bar spraying just the rubbers it raiser rpm's alittle on #2 carb can that be enough to cause my problems ?????????????

[bikerphil]

I would re-do the boot gaskets with new gaskets and yamabond to eliminate any leaks for sure. I did them on both of my XS's this way and never had a problem. Always use some type of fuel resistant RTV with new gaskets and take extra time removing all old gasket material from surfaces. JMHO.

[DGXSER]

I'm with Phil on this one. Sounds like you have a vacuum leak and with your discovery of the boots, I'd say it is still there. You could try the pinto gaskets. I know, despite Doug's love of them it seems like sacrilidge(spelling??) to me to combine a pinto with the XS11. But if that part fixes it, then you gotta love it!

[foreda]

Boots

I had the same problem after changing my boots with new boots. Where did you buy the boots. I would be interested to know?? I think I got mine from Sirius or George's. Might be on to something!!

[Guest]

Boots

i bought the boots from Georges i think they are all made by same co. just sold by different business, beside the carb boots do you think that rubber on the choke bar when i sprayed raised the r's a little. not ever having to deal with this problem before being new to these bikes how much of a vac leak does it take to make it run this bad ??? it sounds like a common problem it could 2 or more leaks just trying to find them i feel like a dog chasing his tail!!!!
thanks for the input guys it all helps

[foreda]

Old boots

I have been tempted to put the old boots back on just to try?? The only reason I changed them was cosmetic only. I know what you mean about chasing you're tail. I can get different results from different sets of carbs as well. Weird to say the least!!

[oldnortonrider]

I'm with Phil on this one. Sounds like you have a vacuum leak and with your discovery of the boots, I'd say it is still there. You could try the pinto gaskets. I know, despite Doug's love of them it seems like sacrilidge(spelling??) to me to combine a pinto with the XS11. But if that part fixes it, then you gotta love it!

?? What are "pinto" gaskets? ??"Pinto" Ford? Where to get 'em?

[bikerphil]

?? What are "pinto" gaskets? ??"Pinto" Ford? Where to get 'em?

The Ford 2.3 L thermostat housing gasket can be used between the carb boots and the head. They'll just need a little trimming on the outside but the bolt holes line up good. Any auto parts store should carry them.