86 SEi stumbles at takeoff.

[Guest]

Hi All!
I have a 86 SEi that I got a few months ago, I have changed oil & filter, air cleaner, plugs, timing belts & ran a can of sea foam thru w/3 tanks of gas, cleaned and synced the throttle bodies and I still get a little hesitation, or stumble when I first crack the throttle, also on the highway she runs out really smooth but when I close the throttle I get a strong smell of unburned fuel. This bike sat for a about 7 years. Odometer says 48k but I get some oil smoke every now and then when I crank her up. I also changed the waterpump and front tire, back looks good, its a metzeler that was made in Germany. Changed all the fluids and have put a few thousand miles on it, gets around 40mpg @ 65mph.
Any Ideas?

[neoracer]

first thing that comes to mind is the setting on the TPS,also check the air temp sensor because that can throw everything off too

if you dont have the sei supllement or a manual with a fuel injection section let me know can email you the supplement

if you send the email address,pm it dont send thru open forum

[admin]

I agree with Earl, that's where I'd start also.

[roscoepc]

Welcome to the Site!!

Like your bike mine had set for about 7 years. It took about 4-6 month's of running for the fuel injection system to finally start running as good as she does today.. Mine had a slight stumble when cracking the throttle open also, (I think it was the TPS), but she finally started working correctly. As far as the smoking at start up, that's kinda normal for GL1200 from all my reading. I think you'll find that as you ride the bike more and more, that should start clearing up also.

If it were me, I'd keep an eye on the oil level, check the CFI computer for a fault light occasionaly and ride her for a few month's and see if she straightens herself up on her own..

Good luck with her!! 8)

[Guest]

Hi there...In your post I didn't read that you changed the fuel filter.
On my '85 Limited, I have found, changing out the fuel filter can work wonders for
response and extra pep and smoothness.
They're still available from the Mothership for about $32 here in Canada...should be
a little cheaper for you.
Good luck and keep us all posted...with only a small percentage of these fuelies on the road, we can help each other keep them going.
I have 209,000 kms. on mine right now, and she stills puts a smile on my face every day.

[nessy357]

first thing that comes to mind is the setting on the TPS,also check the air temp sensor because that can throw everything off too

if you dont have the sei supllement or a manual with a fuel injection section let me know can email you the supplement

if you send the email address,pm it dont send thru open forum

I'm having the same problem with my 85 SEi ? just pulled the fuel filter, and it's plugged with rust, bike had sat for two yrs.
Would it be possible to obtain a the SEi supplement manual also ?
Cheers Bob.

[nessy357]

Wow that was fast, thanks so much, hope I can return this favour.
I'll keep you updated.
Cheers Bob

[catman]

I agree with all the posts odds are TPS but Like RoscoePC and downhomr I would start with the obvious= Fuel filter and then a few cans of sea foam then re-check the synch-- also is this a stumble on a cold engine or just hot or all the time? As far as the smoke- try keeping the bike upright for 30 seconds after you shut her off- I usually hold it up sitting in the saddle and take off my gloves and unstrap my helmet, etc. Since doing the 30 second delay I have less smoke(make sure the oil viscosity is correct too). There are much more knowledgeable folks on here than I but I can tell you that adaptation to a 24 year old bike is really important- don't think she will run like a brand new bike-- but at the same time don't sacrifice performance for safety.

[mrgeo41]

Mine sat some place for a while, the air cleaner had a cup and a half of rat poison pellets in it. It stumbled at take off also, one day in the middle of a U turn it did it an down I went crossways in the road! It turned out to be the main fuse that time, it let me down completely after I restarted it. I only had to push it a quarter of a mile home. The main fuse was a 50 amp on the LTD after it was replaced it run again and much better. I am also running premium gas with a strong mix of injector cleaner, all of which seems to be helping. New plugs also, I didn't gap them, and will asap. God been Good to mrgeo41. **==

[roscoepc]

50 Amp main fuse???? hock: The main fuse on the starter selinoid should be 30amps max along with the inline 30amp sub-main fuse located behind the starter selinoid....

[ghostrider52005]

Ditto on the main fuse. Mine is a 30 amp also.

[admin]

Mine sat some place for a while, the air cleaner had a cup and a half of rat poison pellets in it. It stumbled at take off also, one day in the middle of a U turn it did it an down I went crossways in the road! It turned out to be the main fuse that time, it let me down completely after I restarted it. I only had to push it a quarter of a mile home. The main fuse was a 50 amp on the LTD after it was replaced it run again and much better. I am also running premium gas with a strong mix of injector cleaner, all of which seems to be helping. New plugs also, I didn't gap them, and will asap. God been Good to mrgeo41. **==

Should be a 30 amp fuse on the main electrical and a 50 amp fuse on the external alternator main circuit from the battery. Your bike will run better if you use regular gas as opposed to premium. Premium gas burns too slow, uses more fuel and drops the power off in these bikes. You should only use injector cleaner sparingly as it can cause more problems than it fixes if used for an extended period.

[mrgeo41]

Mine sat some place for a while, the air cleaner had a cup and a half of rat poison pellets in it. It stumbled at take off also, one day in the middle of a U turn it did it an down I went crossways in the road! It turned out to be the main fuse that time, it let me down completely after I restarted it. I only had to push it a quarter of a mile home. The main fuse was a 50 amp on the LTD after it was replaced it run again and much better. I am also running premium gas with a strong mix of injector cleaner, all of which seems to be helping. New plugs also, I didn't gap them, and will asap. God been Good to mrgeo41. **==

Should be a 30 amp fuse on the main electrical and a 50 amp fuse on the external alternator main circuit from the battery. Your bike will run better if you use regular gas as opposed to premium. Premium gas burns too slow, uses more fuel and drops the power off in these bikes. You should only use injector cleaner sparingly as it can cause more problems than it fixes if used for an extended period.

I cannot grasp higher octain burning slower than lower octain. Not questioning comment just wondering why? GEO

[admin]

It's a long story but to put it in a nutshell so you can grasp the gist let me just say that high compression engines must use premium gas otherwise detonation (pinging) will occur. Under such high compression the fuel/air mixture ignites and burns rapidly and sometimes dual or more flame fronts develop in the combustion chamber so to reduce the fuel burn speed high octane (premium) fuel was developed to address this situation. All GL1200's utilize low compression in their engines and the problem with using premium fuel in a GL1200 is that since it burns so slow it does not make as much power, fuel economy suffers and it creates more heat since the fuel is still burning as it goes out the exhaust pipe. What is needed for low compression engines like our GL1200's is regular gasoline (low octane) which burns much faster which in turn makes it more compatible with our GL engines. A lot of guys think that they are doing good for their GL1200 engines when in fact they will do it more good by running a regular grade of gasoline and save dollars while they're at it. Regular gas has an octane rating of 87, midgrade gas is 89, and premium is 91 or 92 or better for racing or aviation gas. I should also mention that if your GL1200 pings while accelerating you don't need premium gas instead what you need is to decarbonize the combustion chamber by either doing several full throttle runs down the dragstrip or if you're not into performance driving pick up a can of combustion chamber cleaner and that should cure the problem. I hope you got the gist of what I'm talking about here because a full explanation requires several pages to lay it all out which I don't have time for this week but you can also look it up yourself online: <!-- m --><a class="postlink" href="http://www.google.ca/search?sourceid=navclient&hl=en-GB&ie=UTF-8&rlz=1T4GGHP_en-GBCA426CA426&q=premium+gas+versus+regular+gas">http://www.google.ca/search?sourceid=na ... egular+gas</a><!-- m -->

[mrgeo41]

It's a long story but to put it in a nutshell so you can grasp the gist let me just say that high compression engines must use premium gas otherwise detonation (pinging) will occur. Under such high compression the fuel/air mixture ignites and burns rapidly and sometimes dual or more flame fronts develop in the combustion chamber so to reduce the fuel burn speed high octane (premium) fuel was developed to address this situation. All GL1200's utilize low compression in their engines and the problem with using premium fuel in a GL1200 is that since it burns so slow it does not make as much power, fuel economy suffers and it creates more heat since the fuel is still burning as it goes out the exhaust pipe. What is needed for low compression engines like our GL1200's is regular gasoline (low octane) which burns much faster which in turn makes it more compatible with our GL engines. A lot of guys think that they are doing good for their GL1200 engines when in fact they will do it more good by running a regular grade of gasoline and save dollars while they're at it. Regular gas has an octane rating of 87, midgrade gas is 89, and premium is 91 or 92 or better for racing or aviation gas. I should also mention that if your GL1200 pings while accelerating you don't need premium gas instead what you need is to decarbonize the combustion chamber by either doing several full throttle runs down the dragstrip or if you're not into performance driving pick up a can of combustion chamber cleaner and that should cure the problem. I hope you got the gist of what I'm talking about here because a full explanation requires several pages to lay it all out which I don't have time for this week but you can also look it up yourself online: <!-- m --><a class="postlink" href="http://www.google.ca/search?sourceid=navclient&hl=en-GB&ie=UTF-8&rlz=1T4GGHP_en-GBCA426CA426&q=premium+gas+versus+regular+gas">http://www.google.ca/search?sourceid=na ... egular+gas</a><!-- m -->

Understood, don't much care for ethanol in lower grade gas, hard to find reg gas with out it. THX for the time. geo.