288xp issues

[kyle.kipple]

A guy brought me his 288xp to work on. I tried to turn him away but he was persistent in having me work on it and said he wasn't in a rush. He bought it new several years back. Within the last 2 years he's had 4 different people workin on it. First time was for fuel system update. Received new lines and filters. Within 2 tanks the top end burnt up. The shop claimed he straight gased it but the owner ran 3 other saws with the same mix that day with no issues. The next shop installed new top end and redid the fuel lines. After that it Runs great for 30-40 minutes then won't hold idle, searching, revving a bit high then low then die. Third shop installed all new case,bearings, seals, oil pump...still same issues after 30-40 minutes. All parts was oem new.
I tore it down to inspect and noticed the throttle trigger was broke on one side causing slop and not allowing full throttle and a broke top AV mount. I replaced both and cleaned the carb. I just came back from testing it to see if I could experience the problem myself. 30 minutes I couldn't tune the L. In the cut she runs get and my tach shows 12,500 at WOT. Want some advice from others more experienced with these models. I believe once it gets nice and warm the seals are experiencing a small air leak. When the saw is hot and idling correctly if you tip it on its side the rpms drop noticeably. Any tips?

 

[huskyboy]

Carb or air leak somewhere is probably the issue, I had a 044 that would keep going lean and the gaskets in the carb were stiff and old, new carb kit solved the issue.

 

[kyle.kipple]

Carb or air leak somewhere is probably the issue, I had a 044 that would keep going lean and the gaskets in the carb were stiff and old, new carb kit solved the issue.

Makes sense but I would think if that's the problem here it would do it all the time from the get go.

 

[mdavlee]

Check the throttle shafts in the carb body

 

[Simondo]

A guy brought me his 288xp to work on. I tried to turn him away but he was persistent in having me work on it and said he wasn't in a rush. He bought it new several years back. Within the last 2 years he's had 4 different people workin on it. First time was for fuel system update. Received new lines and filters. Within 2 tanks the top end burnt up. The shop claimed he straight gased it but the owner ran 3 other saws with the same mix that day with no issues. The next shop installed new top end and redid the fuel lines. After that it Runs great for 30-40 minutes then won't hold idle, searching, revving a bit high then low then die. Third shop installed all new case,bearings, seals, oil pump...still same issues after 30-40 minutes. All parts was oem new.
I tore it down to inspect and noticed the throttle trigger was broke on one side causing slop and not allowing full throttle and a broke top AV mount. I replaced both and cleaned the carb. I just came back from testing it to see if I could experience the problem myself. 30 minutes I couldn't tune the L. In the cut she runs get and my tach shows 12,500 at WOT. Want some advice from others more experienced with these models. I believe once it gets nice and warm the seals are experiencing a small air leak. When the saw is hot and idling correctly if you tip it on its side the rpms drop noticeably. Any tips?

Seal drawing air will as likely ..rase.. the rpm due more air not drop the rpm. Sounds more like a excess fuel situation from puddling in the intake from a posable over rich L setting .

 

[kyle.kipple]

Check the throttle shafts in the carb body

Looking for play I'll assume?

Seal drawing air will as likely ..rase.. the rpm due more air not drop the rpm. Sounds more like a excess fuel situation from puddling in the intake from a posable over rich L setting .

Makes some sense. But would a bad tune/carb outa adjustment cause rpm shift from tipping the saw over on its side?

 

[mdavlee]

Looking for play I'll assume?

Makes some sense. But would a bad tune/carb outa adjustment cause rpm shift from tipping the saw over on its side?

Yes. The shafts and body can get slop and suck extra air there

 

[Simondo]

Looking for play I'll assume?

Makes some sense. But would a bad tune/carb outa adjustment cause rpm shift from tipping the saw over on its side?

If the L side of the carb is giving to much fuel then yes it can . You can also see if you let the saw idle for 20/30 seconds and then without revving it ,stand it on its nose. The saw can bog if its puddling and as you said you were having trouble setting the L there may be a carb component /set up situation. You would hope the seals that went in are ok but a pressure vac test will tell you some more info on that .
mdavelee' point about the shafts is another place you get odd tuning issues.

 

[kyle.kipple]

If the L side of the carb is giving to much fuel then yes it can . You can also see if you let the saw idle for 20/30 seconds and then without revving it ,stand it on its nose. The saw can bog if its puddling and as you said you were having trouble setting the L there may be a carb component /set up situation. You would hope the seals that went in are ok but a pressure vac test will tell you some more info on that .

Will try the nose trick tomorrow. When first started it performs flawless so I need to let it run a good bit before it starts being a pain. Also planned on bringing the mighty vac home from work tomorrow to test seals

 

[jb-chainsaws]

Seal drawing air will as likely ..rase.. the rpm due more air not drop the rpm. Sounds more like a excess fuel situation from puddling in the intake from a posable over rich L setting .

I'm with Simon on this, the drop in rpm sounds fuel related, and over fuelling at that. I agree it could be fuel pooling in the intake. Set it idling and tip it forward after a few minutes still at idle. If It drops revs and nearly cuts out you have your problem

 

[srcarr52]

It could be a leaking governor circuit. Most 288 had governed carbs.

 

[psuiewalsh]

Check the intake block. Could be a hairline crack.

 

[pro94lt]

Check the intake block. Could be a hairline crack.

 

[Czed]

Check for spinning crank seals had a couple over the years a crank seal would hold pressure for a while then spin wearing out the bearing seat lol

 

[tree monkey]

tank vent

 

[rattler]

It could be a leaking governor circuit. Most 288 had governed carbs.

That's what I was thinking.

 

[kyle.kipple]

I've been babying a sore back most of this week so I've been lounging after the 10 hr work days. It's a shame I'm dealing with a bad back at 28. Anywho. Ran the saw at idle for 10-15 mins to get good and warm then went and tipped the saw on its nose. 3-5 seconds it died. Repeated only with the same results. I ordered a oem kit for the carb several days ago. Pulled the carb and checked the intake block and it looks good to me. Threw the kit in the carb and took the carb to stock setting. Which on the documents I have is 1 1/2 L 3/4H. Fired up and set idle at 25-2600 and walked away for 10-15. Tipped on its nose and every other direction with no stumbles. Time to slap the bar on and go horse it a bit. Thanks to all that gave me their 2 cents. Much appreciated.

 

[danimal]

Good going guys!
A place where knowledge and opinions are shared..

 

[Chainsaw Jim]

I might get 1 out of 100 saws across my bench that doesn't need a new carb kit.

 

[psuiewalsh]

I might get 1 out of 100 saws across my bench that doesn't need a new carb kit.

Do you buy kits from Dave? I have used a few and they were good.