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Posted

My 83 1200 has a nasty little habit of hesitating when coming out of a corner then wanting to accelerate out of it. Carbs have been rebuilt, plugs replaced. Acts fine otherwise. Anyone else dealt with this before?

Great site !!!

Posted (edited)

Try enrichening the idle circuit; ie: back out the mixture screws a ¼ turn at a time until the hesitation dissipates.

 

Check your carburetor synchronization, too.

Edited by Prairiehammer
Posted

Thx Guys. Now let me give you the long version. This hesitation has been gong on for several YEARS (UGH) and though various shops. The hesitation was there on the 1200 carbs and one shop screwed up the carb body so the float value would not hold. So new rebuilt 1300 are on there. Synced, on a Dyno as well, but the hesitation persists.

Now let me give you the real scary part of this. Though my ego tells me I shouldn't say this my need to correct this problem is more important. While the 1200 carbs were on there and one cold day I left the house and at the corner I had my beauty go out from under me. Only damage was scraped up crash bars(since rechromed). After the bike was picked up. Ready for this...... it ran perfectly for over thee months. Perfect in everway. Took it on some road trips. It was great till the throttle cable snapped and I took it for repair. When I got it back it was back to same old hesitation. I asked what was done and was told that all was replacing the cable and resynced the cabs, but something else had to be disturbed and now I am still trying to find the problem. The lean is more toward electrical as the problem persists through two different sets of carbs.

Any thoughts?

THx

Posted

I might be suggesting something that just creates work, but the rubber pipes (connecting between inlet and carb) also connect to some vacuum chambers. It is just possible that someone has disturbed a connection. Donkeys years ago before the big split in Venture websites the 'other' site had a lot of stuff on testing those chambers for leaks. It might be worth testing that they seal and that the hoses are seated properly - they're thirty years old and if you are anything like me, they've been forgotten about most of that time. Airleaks could make it stutter on take-off.

 

Or I might have given you a red herring to fish for...

Posted
Sea-Foam!!:whistling:

 

Dan, my 89 has hesitated since the day I got it.

I have run it on nothing but Sea-Foam for a year. Same problem.

I'm wondering if it will run better on gas. What do you think?

Posted

Have you sprayed WD40 or starting spray around the carbs bases. If you find an area that the rpms jump up slightly you have a leak. Mine was not running right untill I found a vacuum leak in the Orings under the intake boots. Replaced them and the bike ran right after that.

Good luck

Posted

Thanx for the replies. The Sea Foam sound like the way to go. Wonder what kind of milage I would get compared to Gas.....

Anyway the vacuum we'll check out, but I think it was considered when the 1300 carbs were installed, but surely something could have been missed. ANy other ideas would be appreciated as scratch my head has done much but made my head hurt:depressed:

Posted (edited)
Thanx for the replies. The Sea Foam sound like the way to go. Wonder what kind of milage I would get compared to Gas.....

Anyway the vacuum we'll check out, but I think it was considered when the 1300 carbs were installed, but surely something could have been missed. ANy other ideas would be appreciated as scratch my head has done much but made my head hurt:depressed:

 

If you installed 1300 carbs on an 83, you may have the wrong TCI. Where did you connect the Boost sensor hose to on the carb/manifold? On the 83 carbs the hose connects to the carb which is above the throttle plate. The 1300 carbs do not have a port on the carbs to hook the hose. If the hose is connected to the manifold, it will need to have an 84 up TCI.

RandyA

Edited by Venturous Randy
Posted

Yeah, what Randy (Venturous) said, the 1200 carbs have a different vacuum pickup port location than the 1300 carbs. Timing will be different. Someone more knowledgeable than I can explain the difference to you. Although if you had the problem with the original carbs, I don't know if the vacuum hose location is the problem.

 

 

Jim

Posted

Since the bike tipped over and started to run right, maybe the tipover switch is somehow involved. Try replacing it or bypassing it for a short test ride.

Posted

Thx and I have replaced the "trip over" switch and the "dropped" switch...Didn't help:cool10:

 

I did not know there is an auto advance on the bike. Worth pursuing. It is something that got jarred, then everything worked great. Until it went back into the shop for something unrelated. when installing the cable or when syncing up the carbs it must have been disturbed and went back to acting the same. I just have a feeling that it is something simple and when found it will be one of those. "Oh good grief, that's all it was" type things

 

The vacuum pick up for the 1300 carbs was checked and is correct and like mentioned this was happening on the 1200 carbs as well

 

All ideas are good. Some just better than others....thx:lightbulb:

Posted

You need to look at the number on the TCI, which is located under the battery box and see what the part number is. If it starts with 26, you have the wrong TCI for the 1300 carbs. No matter what your situation was with the 83 carbs before, the 83 TCI does not work correctly with the 1300 carbs. You need to eliminate the known things that are not right before you go on a wild goose chase.

One problems with syncing carbs is any vacuum leak must be fixed before the sync is done. Otherwise, the sync will try to include the leak and once you go off idle, the sync may be way off.

One more thing, where is the vacuum hose hooked to on the carbs right now? You said this was checked, but by who? Most Yamaha mechanics know very little about these bikes.

RandyA

  • 6 months later...
Posted

Seems that I took the bike in and they accidentally put their finger through the level window. They patched it up with JV weld which, in my experience, will not last long with brake fluid. I have start looking to find another master, but though they were used through "93" the part is obsolete. Tried EBAY didn't find one. Thought I would ask if any one knows or has for sale a clutch master for my wonderful "83"...thx

Posted
Seems that I took the bike in and they accidentally put their finger through the level window. They patched it up with JV weld which, in my experience, will not last long with brake fluid. I have start looking to find another master, but though they were used through "93" the part is obsolete. Tried EBAY didn't find one. Thought I would ask if any one knows or has for sale a clutch master for my wonderful "83"...thx

 

I'm a simple, if somewhat bitter, man. If THEY put THEIR finger through it, THEY can fix it properly to the OWNER's satisfaction. I'd be doing some service-desk dancing.

Posted
Seems that I took the bike in and they accidentally put their finger through the level window. They patched it up with JV weld which, in my experience, will not last long with brake fluid. I have start looking to find another master, but though they were used through "93" the part is obsolete. Tried EBAY didn't find one. Thought I would ask if any one knows or has for sale a clutch master for my wonderful "83"...thx

 

Don't replace the entire reservoir, just replace the sight glass. Give this link to your repair facility manager and have them fix it correctly.

 

http://newrivercyclesalvage.com/sight-glass.html

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