husky 435 bogs when I try to rev it

[mountainlake]

It could be the coil, after you get the piston in try running it with the old coil first. I think the wear on the piston skirt on the intake side was the problem. Steve

 

[GRT Ranch adventures]

You may just have the primer hooked up wrong. It does NOT inject fuel into the carb, it sucks fuel out of the carb and dumps it back into the tank and it MUST be connected to the right carb port. The fuel line from the tank should go to the carb fitting that is on the fuel pump end of the carb and the suction tube from the primer should go to the carb fitting that comes from the fuel chamber under the main metering diaphragm. When you depress the primer bulb you should feel fuel being squished through it and if you look in the tank you should see fuel coming out of the tube coming from the primer. If these things get incorrectly hooked up so that the fuel has to go through them to get to the carb, it will act as a serious restriction in the fuel delivery and show up as a bog when the engine needs more fuel than at it does at idle.

im still 90% sure it was hooked up correctly but i double check when i put it back together

 

[GRT Ranch adventures]

It could be the coil, after you get the piston in try running it with the old coil first. I think the wear on the piston skirt on the intake side was the problem. Steve

thats my plan, only replace one part at a time until i find the problem. generally i don't like just throwing parts at something until it words but that's where i ended up on this one lol

 

[leaf]

Here's the video of how it was running

We can't hold the saw in our hands and "try" with it. BUT I believe you can "put aside" some of the possible factors in favor of others. This is one of the saws that has one of those "single stack, double throat" vertically oriented carburetors, a relatively small impulse connection, a relatively short needle, and a non-usual path up to the main jet (special tool to replace the welch plug, etc.). When they are working, these carburetors do work -- although not uncommonly with somewhat unusual positioning of the mixture screws. I have no statistics, but I would make an even bet that when these things clog / stick etc. and less-than-completely-careful people rebuild them, they have a significantly greater continued failure rate than other chainsaw carbs.
So, I would put aside, for example, the coil. Pull the plug, ground the threaded end, turn the saw over, and if the plug goes zap,zap,zap put it back in and focus on fuel. Check the fuel line, tank vent, bulb (pump a bit, check flow), etc. and put that aside (assuming all the signs are good).
Now, go back to the carb, take it out pretty gently and sorta slowly. As you take it out, observe the black "surround" object between the carb and the jug -- any cracks in the rubber area around the outside of it? Was the carb and that "shield" all sitting flat and clean? Lined up on the little pin? And the little impulse hole lined up both as it comes out of the jug and goes into the carb (the one offset from the other)...? Now shine a light and take a little piece of wire and make sure the little hole on each side of the impulse route is open.
Then it is probably worth pressure testing the carb if there is any way you can. Then carefully disassemble the carb -- and put it back together VERY carefully, be "surgical environment" clean about all of it, while using suitable small pieces of wire, an air pistol, and a vac pump. Take the trouble to make sure of just about everything, that the diaphragm is moving correctly, that the little lever that moves the fuel needle is at exactly the right height, that the path up to the main jet is clean, etc. etc. etc. Make sure you don't have any mixture screw "limiters" restricting ("helping") you. Get a little "serrated" mixture screw adjuster. (Ebay $2) Screw in gentle-firm then out 1-1/2 to 2 low and at least 2 turns high. Make sure that the "top" of the carb isn't stuck open, is fully closed until throttle-up. If in doubt, you can open the high speed jet to 3 full turns. (it is not uncommon with these saws to find that it is not easy to "over fuel" the high speed screw. Many of them, you can keep turning out without making the mixture rich enough to ... really act rich.)
When you put the carb back into the saw, again very carefully, my guess is that the saw will work.

 

[farmguywithasaw]

We can't hold the saw in our hands and "try" with it. BUT I believe you can "put aside" some of the possible factors in favor of others. This is one of the saws that has one of those "single stack, double throat" vertically oriented carburetors, a relatively small impulse connection, a relatively short needle, and a non-usual path up to the main jet (special tool to replace the welch plug, etc.). When they are working, these carburetors do work -- although not uncommonly with somewhat unusual positioning of the mixture screws. I have no statistics, but I would make an even bet that when these things clog / stick etc. and less-than-completely-careful people rebuild them, they have a significantly greater continued failure rate than other chainsaw carbs.
So, I would put aside, for example, the coil. Pull the plug, ground the threaded end, turn the saw over, and if the plug goes zap,zap,zap put it back in and focus on fuel. Check the fuel line, tank vent, bulb (pump a bit, check flow), etc. and put that aside (assuming all the signs are good).
Now, go back to the carb, take it out pretty gently and sorta slowly. As you take it out, observe the black "surround" object between the carb and the jug -- any cracks in the rubber area around the outside of it? Was the carb and that "shield" all sitting flat and clean? Lined up on the little pin? And the little impulse hole lined up both as it comes out of the jug and goes into the carb (the one offset from the other)...? Now shine a light and take a little piece of wire and make sure the little hole on each side of the impulse route is open.
Then it is probably worth pressure testing the carb if there is any way you can. Then carefully disassemble the carb -- and put it back together VERY carefully, be "surgical environment" clean about all of it, while using suitable small pieces of wire, an air pistol, and a vac pump. Take the trouble to make sure of just about everything, that the diaphragm is moving correctly, that the little lever that moves the fuel needle is at exactly the right height, that the path up to the main jet is clean, etc. etc. etc. Make sure you don't have any mixture screw "limiters" restricting ("helping") you. Get a little "serrated" mixture screw adjuster. (Ebay $2) Screw in gentle-firm then out 1-1/2 to 2 low and at least 2 turns high. Make sure that the "top" of the carb isn't stuck open, is fully closed until throttle-up. If in doubt, you can open the high speed jet to 3 full turns. (it is not uncommon with these saws to find that it is not easy to "over fuel" the high speed screw. Many of them, you can keep turning out without making the mixture rich enough to ... really act rich.)
When you put the carb back into the saw, again very carefully, my guess is that the saw will work.

Lol you can hear that it’s the coil. It’s not advancing the spark when you go to rev it. I had pretty much the same problem with my 445. It had no spark when I got it. They sold me a coil for a 445 e not an e ii

It would run exactly like that but it would not advance the spark as it was not correct to the flywheel timing on the e ii

I tested this before going back for the right coil by squirting fuel mix into the intake WITHOUT the carb on it. It should rev to the moon as it leans out but it didn’t it ran just like that

 

[pioneerguy600]

If that black color on the piston is not a coating like some teflon coated pistons and is indeed carbon the the ring has been slack for a long time, I have never seen that much blow by on any saw in all my years of wrenching. The ring looks to be free to move in the groove/land so it must just be badly worn,strange indeed.. I would be interested in seeing the rig end gap numbers.

 

[Tomos770]

Maybe it is its aftermarket Chineesium CDI....?

 

[sean donato]

If it had been leaking air it would have been idling fast. Steve

They don't always present as a screaming high idle, and most would attempt to tune it out. Had enough issues with my old 435 when it wad new to know its a really crappy design and not always easy to diagnose when it come to running issues. Over complicated fuel system, poor intake design and poor choice for sealant lead down many rabbit holes. Heavy use didn't help it any either. Point being they are notorious for getting small air leaks, that are easily over looked.

 

[mountainlake]

Been a long time, did you get it running yet. Steve

 

[Gord404]

just a wild guess but maybe the coil has lost it's brains - could replace it with a cheap china one and if it works then replace it down the line with oem

 

[sean donato]

Husqy coils are like $30 odd bucks. Just replaced one in a 450 last week. Wouldn't bother with a China job at that price.

 

[GRT Ranch adventures]

sorry ive been busy with some other stuff, my parts finally showed up and i got the saw back together. it is definitely running better but after i put it together i started it without the chain and bar and instinctively put the chain brake on to start it but with no chain i forgot to release it and tried to rev the saw for about 20 min before i realized what was going on and now the brake is hanging up and getting hot when i try to run it... for the record the brake did not hang up before and i even tried to run the saw without the clutch cover, brake is in the cover, and it still bogged. now if i take the cover off it idles and revs the way it should but i have the brake problem to sort out. new parts so far are: piston and cylinder, coil, carb, spark plug, fuel filter, air filter, insulator and a top cover clip. almost a new saw by now lol

 

[farmguywithasaw]

 

[Tomos770]

 

[GRT Ranch adventures]

If that black color on the piston is not a coating like some teflon coated pistons and is indeed carbon the the ring has been slack for a long time, I have never seen that much blow by on any saw in all my years of wrenching. The ring looks to be free to move in the groove/land so it must just be badly worn,strange indeed.. I would be interested in seeing the rig end gap numbers.

i put the ring in the cylinder to look at it but dident have feeler gauges handy to my eye looked like about .015" or so the new one was notably tighter, maybe .003-.005 just enough to see light through when backlit

 

[pioneerguy600]

i put the ring in the cylinder to look at it but dident have feeler gauges handy to my eye looked like about .015" or so the new one was notably tighter, maybe .003-.005 just enough to see light through when backlit

15 is a quite large gap but that should not cause that much blackcoating, possibly the rings had lost tension and not sealing as well as they should. I have a Makita 3500 that has the slack tension thing happening.

 

[DirtyHippo]

the primer bulb should be hooked up as follows: the long leg of the bulb should connect to the longer fuel line going direct to the tank. the short leg hooks up to the short fuel line to the carb and the short fuel line from the tanki to the other side of the carb. the primer pulls fuel through the carb and back to the tank. but its not actually a primer per-say, more a purge bulb. it just removed the air trapped inside the carb prior to starting.

the 435's are a historically finicky saw that need more attention to tuning than other saws i've repaird. i would say set the carb jets (L/H) to 1 1/2 on the L and 2 1/4 on the H and tune from there. keep the H needle tuned on the rich side so you get the most RPM but still get enough fuel mix to keep it from squeaking the piston. there;s plenty of YT videos available to help you tune it properly.

 

[GRT Ranch adventures]

heres the video of me running it with the chain brake on for anyone interested, what i thought was a tuning issue im not so sure is tuning anymore. ive noticed that while the chain starts out free to spin when i start the saw after just a few seconds it gets tight and the cover gets hot, so i need to do some more investigating on the brake now but something is hanging up.

 

[rupedoggy]

Stop running with the chain brake engaged

 

[Gord404]

probabably fried the worm on the oiler so its not oiling with all that heat.