250ES Low Compression-Carbon???

[bigreddaddy]

I finally got my 250ES to run, for about 4 seconds using starting fluid and carb cleaner in the carb. When it fires up it blows a lot of black carbon smoke out the pipe. I checked compression using the starter and it only reads 90psi.
Could the low reading be from carbon build up?
I know in 2 stroke outboard motors there is this stuff you can mix with your gas and it will break up all the built up carbon on the pistons/cylinders.
I was hoping I could keep it running long enough to blow a lot of it out, but it will only stay running for a few seconds at a time. I guess I'm going to have to take the carb off, just no way around it.
What do you fellas think about the carbon/compression? By the way, I'm sure this trike has been sitting and neglected for years.

[threewheelin-feelin]

if there is carbon build up on the top of the piston you will have a increase in compression....if you have carbon build up on the valves they will not shut and seal good causeing a lose in compression....we have mixed cam 2 race fuel with regular fuel to fix this with cars...but i dont know if its a good idea on a 3wheeler or how much to use.

[junkrider]

An old timer trick is to shoot a little water in the carb intake while running about mid-rpm. You could do this with a squirt bottle (windex style). The resulting water vapor breaks up carbon deposits.

Don't do too much water (no hoses!) and keep it running while you do this.

Sounds nuts, but supposedly it works.

-junkrider

[junkrider]

Although the compression is low (I suspect rings), it sounds more like its just rich as all heck.

Pour about a teaspoon of oil in the sparkplug hole and repeat the compression test. If the compression goes up, its probably rings are bad.

Does the carb leak if you leave the petcock on? (out the vent tube?)

If so, check the post I put on the 225DX thread, how to clean a carb.

Is your plug fresh?

If your carbon buildup is so bad its keeping the valves from sealing, you'll probably need to pull the head. Get a shop manual and you shouldn't have much problem. We can help :).

Good luck

-junkrider

[bigreddaddy]

Although the compression is low (I suspect rings), it sounds more like its just rich as all heck.

Pour about a teaspoon of oil in the sparkplug hole and repeat the compression test. If the compression goes up, its probably rings are bad.

Does the carb leak if you leave the petcock on? (out the vent tube?)

If so, check the post I put on the 225DX thread, how to clean a carb.

Is your plug fresh?

If your carbon buildup is so bad its keeping the valves from sealing, you'll probably need to pull the head. Get a shop manual and you shouldn't have much problem. We can help :).

Good luck


-junkrider






No the carb doesn't leak. I replaced the fuel line going from the petcock to the carb since the old line was cracked and the filter really looked bad.
I'm thinking the carb needs a good cleaning or the settings are off, since the only way I can get it to run is by using the starting fluid and thats for only a few seconds.
I downloaded the Honda service manual and also just received the clymer too. I'll keep posting as I'm sure I'll still need the boards help.
Thanks for the reply.

By the way, what can I get from an autoparts store to clean out plastic fuel tanks?

[tapper190]

when you did your compression test, did you hold the throttle wide open?
tapper

[bigreddaddy]

when you did your compression test, did you hold the throttle wide open?
tapper


Uhmm, no I sure didn't, and I did read somewhere that your supposed to. Does it really make a difference?

[tapper190]

yes it does make a difference, on page 48 of the clymer manual (m455), is the compression test procedure.

[4cylinders]

hey, before you get too far, what does the oil look like? you need to check the valve lash, to make sure the valves are closing all the way too. your compression test will tell you a lot. rings can get stuck in the piston and cause low comp too. just a couple things it could be. oh yea, disconnect the exhaust at the head and try it, could be a plugged exhaust.

[bigreddaddy]

I'll do another test tomorrow. The oil is black. I don't know when the last time this trike was ran, but at least over a year. I have the carb rebuild kit coming next week.
By the way, just in case, what is a good brand piston besides Wiseco? I have looked at several sites including their website and apparantly they don't make a piston for the 250es.
There are 2 piston/ring kits on ebay for the 250es, WSM and CycleCraft.

[bigreddaddy]

I didn't do another compression test today, because I found out that the carb was not getting gas. I cleaned the tank and put new fuel line and tried to start it a few times. I took the line off from the carb to the petcock. Fuel line on carb side wasn't even wet with gas. After taking the line off I double checked the petcock turning it to ON and gas started pouring out like its supposed to.
The carb inlet was very dirty as well as the whole carb. I took it off and cleaned it real good. I haven't taken the bowl off yet as I have a carb kit coming Monday, though if I have time time Sunday I may clean the jets and stick the carb back on to see if it will crank.
I also made progress with the 110. I cleaned its tank out, cleaned the points, checked and do have good spark. I ordered a carb kit for it too.
Oh yeah, and I FINALLY got the the dang recoil working (one day before the new recoil rebuild kit arrived, of course).
I'm taking my time with these two but hopefully will get them both running good soon.

I bought a Yamaha YFM100 4-wheeler (yeah I know) the other day because I got such a sweet deal on it. It runs great. I haven't let my 6 year old son ride it by himself yet, still teaching him and I need to fix the brakes (the only thing wrong with it). But he loves it.
The first thing he said when he saw it was, "cool, but did you get my 3-wheeler running yet?"
Kids!

[bigreddaddy]

The Big Red is now a runner!

Well for the most part. I took the carb off and cleaned it real good, man was that thing filthy! I mean real dirty.
My carb kit is coming tomorrow but I decided to clean it today anyway. I'm glad I did.
I put it back on and started it up. She fired right up. No smoke, no bad noises. I guess the black smoke I saw before was just in the pipe.
It won't idle though. I know that the choke works, and have to keep adjusting it to keep it running. I'm sure the carb settings are off and maybe timing because it will backfire a little, but then again I have to keep moving the choke.
I've got to take it back off and put the new kit in sometime this week hopefully. I'm just glad I got it to run.
I put my hand behind the pipe when it was running and the compression on that end felt real strong.
Anyways, it's a work in progress and it IS progressing.
I'm going to keep posting in case anyone is following this post and in case I need more of the boards help. I also don't want to keep posting new threads so again I'll keep it here.


BigRedDaddy