Problem with after market driven pulley on trail master

[Ryanhodge2715]

I'll definitely try it. Crazy old guy at work mentioned vapor lock??? I needed to drill a hole in the bolt I tapped the motor with?

 

[bob58o]

Ive drilled holes for block venting before but that doesn’t seem like the problem. It seems the spark is good so focus on fuel delivery.

Sometimes the gas caps on the tank do not provide adequate ventilation to let fuel flow out of the tank freely. I’ve drilled a larger vent hole in gas caps before. Besides that fuel filters or lines could get clogged and only allow fuel to trickle. Which might mean the fuel bowl is low on fuel. When hitting bumps, it splashes and the card doesn’t draw fuel properly.

As far as the choke thing…

I’m not sure which jet is installed with new intake and exhaust? 0.038”? 0.039” ? It is possible that if the jet is too small, you can reduce the amount of air (partial choke) and still run ok.

I can’t tell by just looking at the spark plug, but others might be able to tell if too lean by looking at a pic of the plug. Too clean might mean too lean.

I'll definitely try it. Crazy old guy at work mentioned vapor lock??? I needed to drill a hole in the bolt I tapped the motor with?

 

[bob58o]

As far as the vapor lock thing… I've vented from where the governor pivot thing enters the block. From the side cover.. From the valve cover (which is the way these engines come).

Drilling through a bolt is not fun for me and I’d avoid it and look for another way to vent should you choose to do so.

 

[Ryanhodge2715]

Ive drilled holes for block venting before but that doesn’t seem like the problem. It seems the spark is good so focus on fuel delivery.

Sometimes the gas caps on the tank do not provide adequate ventilation to let fuel flow out of the tank freely. I’ve drilled a larger vent hole in gas caps before. Besides that fuel filters or lines could get clogged and only allow fuel to trickle. Which might mean the fuel bowl is low on fuel. When hitting bumps, it splashes and the card doesn’t draw fuel properly.

As far as the choke thing…

I’m not sure which jet is installed with new intake and exhaust? 0.038”? 0.039” ? It is possible that if the jet is too small, you can reduce the amount of air (partial choke) and still run ok.

I can’t tell by just looking at the spark plug, but others might be able to tell if too lean by looking at a pic of the plug. Too clean might mean too lean.

Interesting... never heard of it or seen it in the few videos I seen. Makes me wonder I never had this issue befor the flywheel install an the big air filter. Would either of those call for extra ventilation? An the jets I have come labled. .85 .90 .95 all the others bogged when hitting the gas so I went with .85 it has no hesitation when accelerating. It's what came with the fly wheel.. not sure if there just labeled different or if im wayy to high. But just the idea of a hole going into the block wouldn't dirt eventually build in the engine? An yeah I thought all the motors have to have that blow out our whatever proper term is for the vent on the valve cover.

 

[Ryanhodge2715]

Spark plug was new with the fly wheel as well an it's already covered with carbon probably from me shooting in the dark an quarter turning with each jet trying to tune.

 

[Ryanhodge2715]

Watching my baby boy again rn so can't dig in an get dirty but that's my breather vent. Per say I had that hose at a bit of angle an pinched air flow a little could that be a issue?

 

[BaconBitRacing]

@BrownStainRacing was big into crank vents on modified engines, and he was (IMHO) the best engine builder here.

 

[Ryanhodge2715]

What you think @BrownStainRacing Lol I see alot of people now that I look into it say it's not called for on stage 2 but it's all new to me. All I added was the big air filter and aluminum fly wheel an I'm now having problems. But when I first put it all on no issue right away it was running better then it ever has. Then It began running good for 5 min the spudder out. I changed valve lash and coil gap an it didn't spudder an cut off any more but after I get over half throttle or go bumps it spudders overal lost power i can tell my rpms arent as high.

Also fresh gas line on it no filter on it

 

[bob58o]

It’s not exact… but jets are labeled in mm or inch.

0.85 mm = 0.033”

so an 85 jet is close to 0.033”
100 jet is close to 1.00 mm is close to 0.039”

again not exact

 

[bob58o]

And no, I do not think you should need additional venting, just saying there are easier ways than drilling through a bolt. You can use “breather filters” on the vents to help avoid dirt. And it’s not just a hole. It usually involves tapping for a barb fitting with hose and filter (possible a check valve).

New fuel line is 1/4”?
3/16?”

Too thin of fuel line also can act like a clogged line.

I use 1/4” stuff from “Auto Parts Store”

 

[bob58o]

I believe you mentioned the carb spilled gas overnight before???

This may be a sign that there is gunk in the bowl float needle valve / jet interface.

could be gunk is slowing the fuel flow and also preventing the float needle from seating with the needle jet.

this vid shows the needle and jet I am talking about.

 

[Ryanhodge2715]

Yeah buddy sound like you onto something there didn't know about that needle jet! Be Lil while before I get time to check it out but will Tag back in when I do. Thanks man

 

[Ryanhodge2715]

So I took carb apart no trash at all still sprayed it outta be safe. The seal that the bowl rest against did have 1 twist in it. I took it out an reinstalled properly. Still the same thing. But has to be a air leak I pulled the choke an the sputter went away!! Was running high rpm I feel like it was at first but choke took spudder out

 

[Ryanhodge2715]

I check head gasket seal on side definitely looked torqued to much mashed in so I took the other head cover off the other an same thing.... but also I think one of you mentioned 17 ft lbs of torque on those bolts. They definitely snug pretty good but couldn't get my wrench to click was worried I'd strip it so I left it alone.

 

[Ryanhodge2715]

Also tried my last spark plug that worked fine, wasn't old at all. I just used the new one that was sent with the stuff anyway. But nothing either

 

[bob58o]

To check for air leak around a carb spray some starting fluid around carb gaskets. If the fluid gets sucked in, the engine rpm should change. Can also work with WD-40 or something else. Just listen for rpm change. Might increase or decrease. Don’t spray down the air horn, only around the gaskets where carb connects to head.

if no air leak, then go back to fuel….

Runs better with less air means it likes it richer than it’s getting. Either dirty carb or too small of jets.

Carbs need cleaned by poking every hole with tiny wire.

0.035” - 0.037” is very common on these engines using an open header style exhaust and k&n style cone air filter.

 

[Whitetrashrocker]

Have you tried a new coil? Maybe appease bob0 ?
You have taken everything apart several times and still haven't got it.

 

[bob58o]

Have you tried a new coil? Maybe appease bob0 ?
You have taken everything apart several times and still haven't got it.

i did a bit of assuming that the flywheel was from ARC. I think their magnets are pretty strong. I was thinking that too close of air gap with a ARC magnet would have worsened the coil.

It still might be coil related, but I think his flywheel is correctly gapped at 0.030” or so. And since then I’ve given up on that.

 

[bob58o]

Also might need to fatten up the pilot jet, unless a new one came with the kit. IIRC, the stock pilot jet is around 0.016” and likes around 0.019” with filter and exhaust upgrade. I don’t remember off the top of my head and don’t like those carbs in my builds.

 

[bob58o]

I didn’t watch this video but skipped through it to make sure he was thorough enough to take out pilot jet and poke E-tube and jet holes.

By the time this engines runs properly you will have extracted every bit of small engine knowledge I have. I’m beginning to think you are just an AI training bot.