Kenbar

[compguy101101]

Ok, so here's the problem. I have a Kenbar D-856. The thing just doesn't seem to get up and go like it did when I first got it. I am not the firs owner of it and had to tweak it a little to get it back up and running. But I'll hit the gas and it doesn't have the grab I guess you could say that it had when I first got it. Also It's almost as if the torque converter isn't working because it never get to a decent speed. Any ideas on where to look for potential problem?

Also the engine runs funny. Not sure if it is normal, but, I'll crank it and wait for it to warm and even when it is warm it runs funny. You can here it fire and then 4 perpetually slower compressions then a fire and another 4 compressions. So it sounds like let me try this.... fire bum bum bum bum fire bum bum bum bum. Each bum you can see the chain get tugged on but doesn't move the go kart. And the idle is either like that or it sounds normal but the things wants to take off. So any ideas on the engine?

 

[Russ2251]

Is it misfiring?

 

[compguy101101]

Wow. Wasn't expecting such a quick response. No, it doesn't seem to misfire. It will fire and then not fire for what sounds like 4 compressions then fire. But if you give it some gas. It will fire which increases the rpms significantly and makes the go kart want to take off.

 

[Russ2251]

Sounds like a very rich mixture. Turn low speed (if equipped) slowly clockwise until engine smooths out.
It is also possible that float is stuck or otherwise damaged allowing the rich condition.

 

[compguy101101]

I see. Think you could describe what the low speed would be and whee to look. I kinda of have an idea, but am not familiar with where to look. The float is what someone else mentioned I talked with said it might be. How do I clean the float or get it unstuck?

 

[Russ2251]

Indicated in blue square.
Also from pg. 18 of Tecumseh carb service manual:

 

[compguy101101]

Well I adjusted it and it didnt seem to make the engine do anything. There was no audible change.

 

[compguy101101]

I'll try to get a video of what it is doing so that you can see/hear what I am talking about. Was surprised though that adjusting the low speed did nothing at all. I fly nitro powered model planes and have adjusted the low speed on the tiny hobby engines and have had results of it smoothing the idle out. But adjusting it on my go kart motor didn't do anything. The screw was tightened all the way clockwise when I began adjusting it. Turning counter clockwise just seemed to loosing the screw not doing anything to the performance of the engine.

 

[Blazkowiez]

Indicated in blue square.

Russ, these kart carburetors don't have a fuel mixture screw, what you've highlighted is an idle restriction screw which sits snug in place without adjustment. When people loosen these to make the kart run better the end result is the screw vibrating lose during operation and ending up lost.

If you do loosen this and the engine begins to run better then you need to clean out this jet and re-install it, repeat this process until you do notice that it justs the same fully in place as it does 1-2 turns out.

 

[compguy101101]

So I guess what I need to do is take off the float and clean that? Or is there something else that might be clogged.

 

[Blazkowiez]

The float never gets clogged, the float either is airtight and works or needs to be replaced because it has a hole in it. You can clean the float if its been coated in old gas but thats one of the very first things you'd do when rebuilding one of these smaller carbs.

 

[compguy101101]

Do you have a list of things to tear apart and clean up when cleaning an engine that has sat for a while. Apparently the owner previous to myself let the engine sit. It could probably use a good deep cleaning. All I have done was emptied all the gas out of it, put new fresh gas in with some lucas additive. Changed the oil. Changed the spark plug. And that is about it. Wasn't sure where else needed some attention.

 

[redsox985]

Clean the carb and check the gas tank for gunk build-ups, too.

 

[Randy]

I would suggest before you take anything apart or messing with the set up run some seafoam through it. Put some in the gas and the oil even pour some in to the air intake. This kinda of stuff has brought to life many car and small engines that have sat for a long time. Most recently on my Maxum 1800 with a 3.0 Mercruiser. I had hard starts, throttle bogging down loss of power at high rmps. A bottle of this and the boat has never run better. I had to change props from the previous owner it was running so good. Dont be shocked by the smoke or the crud that will shoot out of the exhaust. It will soon subside. If this doesnt work then somthing mechanical is broken.

 

[redsox985]

I would do routine cleaning and whatnot before I attempt to add a product and run it with something not working/broken.

 

[compguy101101]

Ok well I finally got around to working on the Go Kart. It still has a funky idle but the throttle issue has been fixed. It ended up being the clamp that held the throttle cable slipped so when I hit the accelerator the metal piece that the throttle cable attached to was hitting the throttle cable casing. So I trimmed back the throttle cable casing and adjusted the cable so when you hit the throttle it can get to full throttle. Man let me tell you what a difference that made. It runs like a bat out of hell now. Also came to light that the engine was misaligned with the drive sprocket so I popped the chain as soon as I got it on the trails. So another set back but 2 hours later I was back out there plowing over small trees and generally going where I normally couldn't. Anyone have any tips to get maybe 6.5hp out of this 6 hp Tecumseh motor?

 

[MacfarlaneRacers]

is the starter motor okay? Check If the fuel is going in right.

 

[compguy101101]

It doesn't have a starter on it. It is a pull start.

 

[MacfarlaneRacers]

is the fuel going in ?

 

[KieranM]

Sounds like the coil, i have had engines with the same symptoms, and changing the coil after a bad spark made all the difference.

What colour spark are you getting?