Kat 1100, big loss of horsepower but runs fine.

[darkshark]

Noticed a while back that my 91' 1100 had lost a good amount of horsepower and was running rough/dying at idle. I took it to have the carbs cleaned out, and now it idles/runs beautifully, yet, there's still a huge loss in horsepower.

Does anyone have any idea what I should check first? I was just going to replace the spark plugs and see if that did anything, but beyond that, I have no idea what it could be. Ideas?

[phil823]

umm, check:

spark plugs
air filter
are you sure the carbs are good?
check exhaust flow...is it lacking also?

check compression
check spark! are all your cylinder firing?

[darkshark]

Rode the bike about 50 miles to work today, not only is there a loss in power, but every so often the bike will encounter a HUGE loss in power, to the point where I can't even keep up with freeway traffic at full throttle. Sometimes it goes away by itself, like it never happened, and other times I have to pull over, when I restart the bike it seems fine.

This is my first bike, and although I tinker around, I'm no mechanic, so any help would be greatly appreciated!

[Wild-Bill]

I'd suspect spark. Four possibilities: the plugs, the coils, the wiring and the CDI box. I'd start with the wire connections. See if you've got some corrosion going on.

[phil823]

i concur!

[DClark]

You took apart the carbs, bike runs different, worse. By logic, the problem is in the carbs.

[Kreylyn]

Fuel flow issues (not enough flowing to refill the carbs fully) could cause the issue of loss of power. Check your petcock and lines are not kinked.

Krey

[Wild-Bill]

You took apart the carbs, bike runs different, worse. By logic, the problem is in the carbs.

Missed that. Scratch the electrical issues and look for a kinked fuel line or folded diaphragm spring.

[wfrpalm]

Make sure there are no air leaks before the carbs ( this is possible since that was all apart ). If things aren't sealed good that would cause the problems you are experiencing. Good luck.

[darkshark]

There was this loss in power before the carbs were taken apart. I'm pulling out the spark plugs as we speak, the plastic at the end of plug wire #1 is shattered, so I'm going to suspect that spark plug #1 is bad, however I can't seem to get the darned thing out. I'm using an 18mm spark plug tool, is it for some reason a different size than this?
I'm replacing the plugs with JR9B's, other sources on the internet said this is the right size, I'm hoping they were right.

**edit: Scratch that, did a forum search, the socket walls are too thick, guess it's back to the hardware store!

[DClark]

**edit: Scratch that, did a forum search, the socket walls are too thick, guess it's back to the hardware store!

Don't bother with the hardware store, go to the dealer and see if they have a motion pro socket. It is thin wall and basically designed to get plugs out like what's in the kat. It is well made and I think mind was $11.
If you haven't bought the plugs, get some autolites from the autostore, they'll probably be a lot cheaper, I have seen them as low as $.99 each when there are rebates and they work just as well as NGK's.
Also, look at the sides of the plug caps. if they are cracked, you can replace them or just wrap electrical tape around them (to prevent arcing).

[Wild-Bill]

The 18mm deep-well socket from Autozone works well.

[darkshark]

Actually, turns out, the plugs that were in it were a standard 5/8 instead if 18mm, so I used a regular automotive spark plug tool and an extension to get them out.

I definitely found the culprit as well. the wire leading up to the elbow section of plug wire #4 VERY easily separated out of its housing and came clean off. I didn't happen to buy new wires, so I just replaced the plugs and reassembled it, took it for a test drive, and it for sure seemed A LITTLE snappier, better acceleration, etc, but still not up to par with where it should be, just like before I had replaced the plugs and had the carb cleaned. So I'll update this tomorrow when I get the new plug wires, in the meantime, I have to figure out how the heck to replace spark plug wires on this thing haha.

[Kreylyn]

Actually, turns out, the plugs that were in it were a standard 5/8 instead if 18mm, so I used a regular automotive spark plug tool and an extension to get them out.

I definitely found the culprit as well. the wire leading up to the elbow section of plug wire #4 VERY easily separated out of its housing and came clean off. I didn't happen to buy new wires, so I just replaced the plugs and reassembled it, took it for a test drive, and it for sure seemed A LITTLE snappier, better acceleration, etc, but still not up to par with where it should be, just like before I had replaced the plugs and had the carb cleaned. So I'll update this tomorrow when I get the new plug wires, in the meantime, I have to figure out how the heck to replace spark plug wires on this thing haha.

Unless the wires are damaged or hard further up... just cut 1/2" off the tip to give a fresh connection and rubber, and screw the boots back on.

That would resolve the issue you described.

Krey

[darkshark]

You guys are the most helpful group of people I swear. I really appreciate each and every response!