Another engine running question!

CantThinkOfANam

Hi guys, sorry for posting another engine question but I just want to make sure that I have the problem diagnosed correctly.

I have a new buggy and the shop that I purchased it from put 2 tanks of fuel through it for me. When I brought it home it started after some time and I ran it easy for about 5 minutes.

Now when I start the engine it cuts out after a few seconds and is then really hard to start (and hard to pull cord), there is also some fuel/oil coming out of exhaust when i turn it up. Also, if I try to increase throttle when its started it cuts out.

Would I be correct to say that its flooding? And should I try to lean it out with the low end screw, if so whats the correct procedure.

Thanks for any help.

FuzzyWuzzyWazza

If the cord is hard to pull the it sounds like the engine is flooded, I just leave the glow starter on the plug and wait a minute or so and try to start it again.

When you get it started let it idle for about 30 seconds, then try to rev it, if it is still bogging down the you need to lean it out, you do this by turning the High Speed Needle clockwise. DO NOT turn the Low Speed Needle. Turn it very slightly, 1/8th of a turn at most and see how it runs, a slightly rich engine is safer than a lean one.

You should be getting oil dripping from the exhaust, even in a properly tuned eigine, if it is set rich then you will be getting more oil.

CantThinkOfANam

Okay, I fiddled around with the high speed screw a bit and I got it started. Put 2 tanks through it driving at mid-high pace. I then had to give up trying to start it on the 3rd tank (hand covered in blisters!). It seems to be kicking but seldom starting, and when it does start is stalls after about 10 seconds even with the glow starter on it. And if I try giving it some throttle during those 10 seconds it stalls.

I am finding it hard to understand the relation the high speed screw has on it at idle.

Thanks for your reply.

FuzzyWuzzyWazza

You may have blown the plug, it is quiet normal to go through a plug during run-in of an engine, or at least that is what I am told.

Take it out and have a look at the wire, stick it on the starter and see if it glows. If you get nothing at all then either the plug is dead or the starter. if you get a faint glow, the battery is probably low.

The HSN usually has the fuel line attached to it, so if will have an impact on the mixture at all engine speeds.

CantThinkOfANam

Okay, so I checked plug and it was fine. I decided give it another go (with a glove on!). Same story, fired twice but cutout around 5-10 seconds later. Pull start would also get very difficult to pull, so I removed plug again but to find alot of oily residue on it. Now that plug isn't working anymore. I had leaned the HSN about half a turn.

Really starting to get convinced its getting flooded. What is the LSN for?

Thanks again for your replies.

coolwings

Your tuning settings are incorrect for the engine.
I don't know what make of engine you have or the degree of tightness remaining in it so it's not possible to make a suggestion, other than 3 turns open is a medium setting across many makes.
I suggest that you just drop it back into the shop and ask them to start and retune. Then take a note of the settings it likes so you can put it right yourself later.

CantThinkOfANam

Thanks guys. What I don't understand is the fact that it ran perfect for about 2 tanks. Really crisp and responsive to throttle, didn't stall when applying brakes etc etc.

CantThinkOfANam

Hello again. After a few days away I decided to give it another go. This time I leaned the HSN half a turn and vola! It started on the first pull. Idled fine but seemed a little high on revs (high pitched sound also). It was very responsive to throttle and had a light stream of smoke. However, whenever I gave it more than half throttle it would die down and eventually stop (traveled very fast even on half throttle). Could the HSN be leaned too much?

FuzzyWuzzyWazza

Sounds like it it lean, I would turn the HSN back at least 2/3 of the way, ie: as if you only leaned it out 1/8th of a turn in the first place and see what it is like there.

One other thing to check is the idle gap, this is set with a screw, when you look into your carb from the air intake port, you can see the gap. Check the manual for recommended settings, this changes the amount of fuel entering the engine at idle. If it is too small then the engine will tend to cut out at idle.