Power Loss

TMA1 · 05-09-2009, 10:46 PM

I was out riding most of the day and at starting off from a light up my bike took off just fine then went into a power loss. It felt like one cylinder was not firing. I limped home with little acceleration. When I got home the power loss was still there but it seemed to idle just fine.The next morning the bike ran well for about 15 minutes. It took off just fine but after about 4 miles the power loss came back. It is as if I was driving through mud. Upon limping home the bike would not even make it up the driveway. The engine sounds fine with out a load but when I engage the clutch everything becomes sluggish. Any ideas on what to check?

bladeracer · 05-10-2009, 2:50 AM

Quote:

Originally Posted by TMA1

I was out riding most of the day and at starting off from a light up my bike took off just fine then went into a power loss. It felt like one cylinder was not firing. I limped home with little acceleration. When I got home the power loss was still there but it seemed to idle just fine.The next morning the bike ran well for about 15 minutes. It took off just fine but after about 4 miles the power loss came back. It is as if I was driving through mud. Upon limping home the bike would not even make it up the driveway. The engine sounds fine with out a load but when I engage the clutch everything becomes sluggish. Any ideas on what to check?

Was the engine still revving okay?
Maybe you toasted the clutch and it's slipping?
Are the headers similar temps?
How old are the plugs?

TMA1 · 05-10-2009, 11:28 AM

It Revs well when the clutch is not engaged and sluggish when it is.
The plugs aer new - about 300 miles on them.

Added find - I changed my oil along with the plugs. It was clear a week ago - it is now
black.

bladeracer · 05-10-2009, 11:30 AM

Quote:

Originally Posted by TMA1

It Revs well when the clutch is not engaged and sluggish when it is.
The plugs aer new - about 300 miles on them.

Added find - I changed my oil along with the plugs. It was clear a week ago - it is now
black.

Sounds like toasted clutch then.
Was it the same oil as you were using before?

TMA1 · 05-10-2009, 11:32 AM

Excuse me blade - I don't know about the headers. Nothing else seemed unusual.

TMA1 · 05-10-2009, 11:33 AM

No the exact brand but the same w

bladeracer · 05-10-2009, 11:34 AM

Quote:

Originally Posted by TMA1

No the exact brand but the same w

Both mineral or synthetic though?

TMA1 · 05-10-2009, 11:39 AM

Mineral.

A brief history of me _ had the same bike new back in '82'. never any problems.

Haven't had a bike for 19 yrs. Forgot 1/2 of what I knew.

Some advances made - what oils do you recommend these days. min or syn - what specs and features.

bladeracer · 05-10-2009, 11:43 AM

Quote:

Originally Posted by TMA1

Mineral.

A brief history of me _ had the same bike new back in '82'. never any problems.

Haven't had a bike for 19 yrs. Forgot 1/2 of what I knew.

Some advances made - what oils do you recommend these days. min or syn - what specs and features.

Just use a semi-synthetic.
I use Shell SX4 in all my vehicles but any oil you prefer is fine.
Just change it regularly.
I think you'll have to drain the oil (sounds like it's cooked anyway) and remove the clutch cover to inspect the clutch.
How long have you had this bike?
To me (non-US) the GS series are the two-valve roller-bearing crank engines but I learned recently that the US kept the GS name even in the GSX (four-valve one-piece crank) series.
Do you know which your engine is?

TMA1 · 05-10-2009, 11:58 AM

I will take a look at the clutch - I will bet that is it. I'll change it anyway
It has the dual cam / single crank as is the Original TSCC Engine.
I have had this bike for about 1 1/2 yrs. Got it out of NY with 9300 original miles. I am sure that the clutch has never been changed in those 29 years.
Might be time for a change.

TMA1 · 05-10-2009, 12:02 PM

I pulled the schematic up on SHS PowerSports.

Single Crank - Dual Cam - 16 Valve

bladeracer · 05-10-2009, 12:06 PM

Quote:

Originally Posted by TMA1

It has the dual cam / single crank as is the Original TSCC Engine.

Both are dual cam, single crank though :-)
The old GS engine has a pressed-up crank with big roller bearings instead of shells. To replace the bearings you have to press the crank apart. I only ask because I've never worked on a roller-bearing crank other than single-cylinder engines.

bladeracer · 05-10-2009, 12:07 PM

Quote:

Originally Posted by TMA1

I pulled the schematic up on SHS PowerSports.

Single Crank - Dual Cam - 16 Valve

Cool :-)

TMA1 · 05-10-2009, 12:14 PM

Blade..,
Thanks for your help.
I will post when everything is finished.
About 2-3 weeks.

TMA1 · 05-20-2009, 10:44 PM

Hello Blade:

I'm Back. Well I changed out the Clutch - easy peazy! Went for a ride - 15 - 20 miles was good - new clutch - big difference. 15 - 20 miles more started in with the power loss. Not the clutch this time seems more like air/fuel. I am going to check the mixture this week end and my balance.

bladeracer · 05-21-2009, 9:13 AM

Quote:

Originally Posted by TMA1

Hello Blade:

I'm Back. Well I changed out the Clutch - easy peazy! Went for a ride - 15 - 20 miles was good - new clutch - big difference. 15 - 20 miles more started in with the power loss. Not the clutch this time seems more like air/fuel. I am going to check the mixture this week end and my balance.

Need some more info to be able to guess at what might be causing it.
It's going to be fun to diagnose if you have to ride 20 miles before it starts playing up.
Check that all the headers are similar temp as any cooler ones will indicate a cylinder not firing.
Pull the plugs and make sure they all look the same and aren't too rich or lean.
If you think it's lean you can try taping up half the air intake and see if it's better or worse.