038 magnum High speed changes by 3000rpm

[WearTheChaps]

Thank you again ballisticdoughnut for your help.

 

[WearTheChaps]

Hey @WearTheChaps if you dont have the service and parts manuals you can get them in this thread.

That link seems to be dead

 

[ballisticdoughnut]

Thank you again ballisticdoughnut for your help.

No worries.

 

[ballisticdoughnut]

Should also add, if you remove the black handle cover that flange will slide right on.

 

[cookies]

use a spark plug hole test plug, block it off under the muff and under the carb to test the case/cylinder/seals... no need for special flanges
https://www.ebay.com/itm/1850706581...6ykkEnIy5+yUxHp4E6B0BLAw==|tkp:Bk9SR-zDien6Yg

 

[J D]

use a spark plug hole test plug, block it off under the muff and under the carb to test the case/cylinder/seals... no need for special flanges
https://www.ebay.com/itm/1850706581...6ykkEnIy5+yUxHp4E6B0BLAw==|tkp:Bk9SR-zDien6Yg

I think @Vintage Engine Repairs did a vid on how to make one out of an old plug... had one a while back, been meaning to make another

 

[cookies]

With chinese carbs its always a issue with them using a smaller size of brass tubes for the impulse and fuel inlet, the 038 magnums i have owned used a different carb than the bing and had a compensator top cover with a larger bore throat without the step in it.

 

[cookies]

https://www.ebay.com/itm/3047138120...7h7FoeMe3OiLH12oFkKcG18KGN|tkp:Bk9SR8CKxe36YgI would check your carb guts for sawdust, lifting fuel pump fingers, hardened diaphgram etc and inspect that impulse hose for being tight fitting, not easily twisted on the nipples or splitting. your air leak is small or the carb is unable to fully deliver the fuel demand.

 

[spuldup]

That link seems to be dead

Well I'm a dummy. I linked to a PM. If anyone needs these let me know Ill send them.

 

[WearTheChaps]

Went to check the impulse tube today but ended up with a tear after putting a tear in the manifold.

Google the IPL number of 1119 141 2200 and only copy parts show. One site says it has been replaced by 1119 140 2500 which fits the MS380 381 & 382.

Can anyone confirm this?

​

 

[cookies]

Went to check the impulse tube today but ended up with a tear after putting a tear in the manifold.

Google the IPL number of 1119 141 2200 and only copy parts show. One site says it has been replaced by 1119 140 2500 which fits the MS380 381 & 382.

Can anyone confirm this?

​

can confirm, use oem for the boot and impulse...aftermarket typically does not hold up

 

[DND 9000]

The impulse hose has to be cut to lengh from hose 0000 930 2803. A piece with 102 mm lengh is needed. Intake manifold you need 1119 141 2200.

 

[WearTheChaps]

An update.

Replaced the manifold and impulse line on the weekend and it seems to have fixed the high speed rev problem. Set the revs to 11000rpm and they stay there.. My neighbours will say it was at least a 25 minute test. The impulse line looked good, so my guess is the tear in the manifold started as a pinhole.

The saw now appears to be flooding after stopping the run so another pressure test shows I still seem to have a fuel vent issue. I believe the culprit is the little bleed screws are in soft fuel line.

I finally got a test flange and the crankcase showed no leakage.

 

[J D]

Might just be set a bit rich.
If the fuel vent is blocked it may cause a lack of fuel. Tank pressure shouldn't be enough to overcome the metering valve unless something isn't right with the carb.
If the fuel vent is the type that is just a screw in the vent line be sure to push the screw in rather than screw it in or it will cut a track & seal itself. Likewise, don't push it all the way on or it might seal around the top. I prefer to jam a sintered brass plug in there if I have 1

 

[WearTheChaps]

If the fuel vent is the type that is just a screw in the vent line be sure to push the screw in rather than screw it in or it will cut a track & seal itself.

This is what has happened. The thread marks are very clear.