#3 and #4 cylinders cold

[Surfpilot]

I'm new to this forum, and could use a little help--I'm pretty green, so bear with me. just bought a 1980 GS850 and I've discovered the #3 and #4 exhaust are cold, however it's slightly intermittent. sometimes they'll be hot even after a 5 minute idle, but then I'll go for a ride and 20 minutes later they're cold...other times they're cold after idling and heat up after the ride--or not at all.

I replaced the plugs, and I know I'm getting spark. I'm thinking I just need to clean the carbs. Thoughts? If it's just a carb clean, should I do a carb rebuild in the process?

My other thought was that I should replace the intake boots and the airbox boots...maybe they're leaking??? the previous owner used some kind of silicone around them, which seems to be a tell.

I appreciate any advice I can get, thanks.

[Nessism]

I’d do a full rebuild following the procedures linked in the GSR homepage. Get an O-ring kit from cycleorings.com and get intake boot O-rings at minimum (if your bike has them that is). If the boots are hard and cracked, replace them as well. While you are at it I’d do a valve adjustment unless you know for a fact that they have been properly adjusted within the last 4000 miles. Good luck and welcome.

[tkent02]

I'm new to this forum, and could use a little help--I'm pretty green, so bear with me. just bought a 1980 GS850 and I've discovered the #3 and #4 exhaust are cold, however it's slightly intermittent. sometimes they'll be hot even after a 5 minute idle, but then I'll go for a ride and 20 minutes later they're cold...other times they're cold after idling and heat up after the ride--or not at all.

I replaced the plugs, and I know I'm getting spark. I'm thinking I just need to clean the carbs. Thoughts? If it's just a carb clean, should I do a carb rebuild in the process?

My other thought was that I should replace the intake boots and the airbox boots...maybe they're leaking??? the previous owner used some kind of silicone around them, which seems to be a tell.

I appreciate any advice I can get, thanks.

Do the carb cleaning shown on Bike cliff's site, you don't need a rebuild kit, just get some new O rings and possibly float bowl gaskets.

http://members.dslextreme.com/users/bikecliff/

Adjust your valve clearances also. It will run like it did thirty years ago.

[Larry D]

Welcome.
Would you please go to the User CP, edit your details and enter your location. Also while you're there, edit your signature to include what bike you have. Both will help everyone in the long run, so we don't have to guess where you are and what bike you have. Sometimes there is a member right around the corner to help.

Yes, your carbs should be dipped and rebuilt. Use this.

http://www.thegsresources.com/gs_carbrebuild.htm

Don't waste money on rebuild kits, get your orings here.

http://www.cycleorings.com/

I recommend spending a few days reading and searching this site for info about your bike's problems. There is a huge library of info here.

[Big T]

I'm new to this forum, and could use a little help--I'm pretty green, so bear with me. just bought a 1980 GS850 and I've discovered the #3 and #4 exhaust are cold, however it's slightly intermittent. sometimes they'll be hot even after a 5 minute idle, but then I'll go for a ride and 20 minutes later they're cold...other times they're cold after idling and heat up after the ride--or not at all.

I replaced the plugs, and I know I'm getting spark. I'm thinking I just need to clean the carbs. Thoughts? If it's just a carb clean, should I do a carb rebuild in the process?

My other thought was that I should replace the intake boots and the airbox boots...maybe they're leaking??? the previous owner used some kind of silicone around them, which seems to be a tell.

I appreciate any advice I can get, thanks.

Carb clean as noted, plus replace anything that has silicone on it

I think you'll be pleasantly surprised at how it runs on all 4 cylinders

[almarconi]

Adjust your valves and clean your carbs.

[Don-lo]

add coolant to #1 and 2 pipes

[Surfpilot]

thanks for the advice. I'll definitely re-do the carbs and check the valve clearances. Don-lo, why add coolant to #1 and 2 pipes? what does that do?

[tkent02]

thanks for the advice. I'll definitely re-do the carbs and check the valve clearances. Don-lo, why add coolant to #1 and 2 pipes? what does that do?

Cools them. It was a joke. At your expense. I would advise getting revenge.

[officerbill]

Cools them. It was a joke. At your expense. I would advise getting revenge.

Why tkent? Because revenge is a dish best served cold?
bill

[Surfpilot]

I should have picked up on that as a joke...shame on me.
Well I pulled the carbs out today and will give them a good clean. I found that the previous owner had put a left side intake boot on the #4 intake. Will this create leakage? I would think so because it's backwards...

[Don-lo]

Sorry, I thought the snickery face () would show it was a joke.

but seriously, folks...., this problem could also be caused by #3 & 4 plug wires being switched, although it would run real bad.

[chef1366]

Posplayr lives in Santa Barbara and I vist him often. We may be able to help.