bigger carb for poulan wild thing?

[thompsoncustom]

Gotta be pulse or fuel somehow. Try filling the metering side with fuel before you install it. Make sure your lines aren’t kinked. Check your fuel filter and tank vent. You’ll just have to keep hammering on it until something gives.

Thanks, already tired everything you listed. anymore ideas?

 

[Ketchup]

Big carb will pop on prime?

 

[thompsoncustom]

Big carb will pop on prime?

yes if I spray some fuel down the carb it will pop and run for a sec but does not pull any fuel into the hose. (clear lines)

 

[Ketchup]

With the carb full it should run for a bit before it dies. If it’s running for only a few seconds I think the pulse is too weak to pop the needle in the bigger carbs.
It’s possible it’s partially blocked at the cylinder, though IIRC the pulse inlet is pretty hard to block on a wild thing.
You could try running fuel from a jar instead of the tank. If there’s no change it’s probably not tank related.

 

[thompsoncustom]

With the carb full it should run for a bit before it dies. If it’s running for only a few seconds I think the pulse is too weak to pop the needle in the bigger carbs.
It’s possible it’s partially blocked at the cylinder, though IIRC the pulse inlet is pretty hard to block on a wild thing.
You could try running fuel from a jar instead of the tank. If there’s no change it’s probably not tank related.

well here's another clue and I had kind of the same idea. I took the metering lever spring out of the wt-194 and swapped it over to the hd-12 but no luck it still wouldn't pull fuel. But when I pulled the fuel line off after turning it over the fuel came out of the tank and all the way up the line, I put it back on the carb and still nothing.

It seems the tank is somehow getting pressurized with the bigger carbs instead of pulling a vacuum like it does with the smaller one.....very strange.

 

[Ketchup]

In no way doubting your ability, but are the hoses on the right barbs? I could see the pulse pushing fuel backwards if they were swapped.

 

[thompsoncustom]

In no way doubting your ability, but are the hoses on the right barbs? I could see the pulse pushing fuel backwards if they were swapped.

lol thanks I'm pretty sure there not but I'll flip them around. I've been running the barbbed brass line to the tank and smooth one to the impulse. i do know for sure all the other carbs have been setup right i put on but i didnt pull this one off a running saw.

 

[thompsoncustom]

In no way doubting your ability, but are the hoses on the right barbs? I could see the pulse pushing fuel backwards if they were swapped.

Well I'm glad you said something as I would have never assumed that the lines were backwards but they were. Flipped the lines and it pulled fuel just fine. Sprayed some fuel down the throat and got it running.

Feel like a big dummy as it's not something I even consider I don't know if i've ran into a carb where the fuel side barb is smooth and the impulse is barbed.

I'll have to get out and tune it and see how see runs once it stops raining, maybe tomm if i'm lucky.

 

[Powerstroke Cowboy]

Glad that was a simple fix. Here's a carb off a clone 880. The barbed fitting shown is for the pulse line.

 

[thompsoncustom]

thanks for the pic I'm glad to have it sorted out. both brass fittings are on the right side of the carb I just assumed (which was the problem) the barbed one was for fuel.

ended up running 2 tanks through it today in the rain and I'm pretty happy with how it performed a lot more speed and torque than it had before and was able to keep the stock airfilter just barely so it looks stock. still need to melt/bend the plastic choke lever and install that but that's about it.

will see what the compression ends up at might go back in and add more aluminum in the head and reshape the chamber. Also never measured the squish on this because you can't lower the jug easily but I could just keep adding more aluminum in the top and go back in and cut/sand it out to get what I want.

 

[Powerstroke Cowboy]

Does it feel good for a 40cc saw?

Glad it's working for you so far.

 

[thompsoncustom]

Does it feel good for a 40cc saw?

Glad it's working for you so far.

I've never had any other 40cc saws to compare but it's nothing like it was in the stock form. I'd say it's got a ton of power for a 40cc saw.

closest thing I have to compare it to is my ms260 but that's modded more than this thing and 20% larger.

maybe I'll sign up for a YouTube account one of these days so I can post videos.

 

[thompsoncustom]

Well I figured the youtube thing out....Kind of at least. Let me know what ya think. just running a semi chisel chain.

Timing numbers are 106/121/76

 

[Ketchup]

Well I figured the youtube thing out....Kind of at least. Let me know what ya think

Timing numbers are 106/121/76

Reminds me of my own Wild Thing. I feel like I should have raised my exhaust a bit more. Same for yours, might be worth going to 104.

 

[thompsoncustom]

Reminds me of my own Wild Thing. I feel like I should have raised my exhaust a bit more. Same for yours, might be worth going to 104.

ya it does feel that way. I think I'm gonna end up taking it back apart at some point to get the compression higher with more brazing and may raise the exhaust then.

 

[Ketchup]

Just looked at my notes:

Squish: 0.015” -diagonal band
Base cut: 0.085”
Turbo crank
2x 1” pipe exhaust

Intake: 72/76(cold air)
Transfers: 121
Exhaust: 104.5

Mine is a strato. Runs really hot with a lot of vibrations. I think I have an air leak now.

First thing I see with my numbers is the intake is too high. I wasn’t happy with the strato. I want more rpm. If I do another one it will be the early version.

 

[Powerstroke Cowboy]

looks like it running well. Sound slike it could use some more rpms though. @Ketchup is the lack of rpms the reason you think the exhaust port should be raised?

Also, I am looking at doing the wild thing as well. Just because i've always wanted one. Question. What year did they start the strato? I would like to avoid it.

 

[Ketchup]

looks like it running well. Sound slike it could use some more rpms though. @Ketchup is the lack of rpms the reason you think the exhaust port should be raised?

Also, I am looking at doing the wild thing as well. Just because i've always wanted one. Question. What year did they start the strato? I would like to avoid it.

Yes on the RPM and higher exhaust. People have hit 17k RPM with Wild Things.

It should have plenty of intake with that big carb. So the exhaust side is probably what’s holding it back. Unless that HD 12 is a knockoff. Then it could be flowing less than the stocker.

@thompsoncustom, how much muffler outlet do you have? You might get more RPM by going bigger there.

Don’t take anything I say too heavily though. I’m just a weekend hack. It’s already running pretty good!

 

[thompsoncustom]

Yes on the RPM and higher exhaust. People have hit 17k RPM with Wild Things

I'd say my ms260 I ported is around there exhaust on that tho is at 98 I believe and the exhaust is 150% of the port.

I do need to check the muffler again as I opened it up a long time ago and have no idea what % it is you the exhaust port.

weekend hack huh lol well I guess I'm in the category as I only work on my stuff and have only had a couple saws compared to most on here.


here is some pics of how close the air filter is to barely fitting

 

[thompsoncustom]

well pulled it back apart was bothering me than I never measured the squish.

squish came in a .045 which is better than I thought it would be.

gonna do more brazing on the cylinder. would like to take the squish down to .010 just don't know if the starter can handle it. not worried about the piston running into the top if it happens it happens.