Trouble shooting ideas anyone?

Discuss fixes, upgrades and modifications to your M37

Moderators: Cal_Gary, T. Highway, Monkey Man, robi

Post Reply
User avatar
jbxx
SGT
SGT
Posts: 193
Joined: Sat Oct 20, 2007 5:53 am
Location: Mill Valley

Trouble shooting ideas anyone?

Post by jbxx »

Couple of weeks ago my sled started idleing poorly.
Actually wouldn't idle, would die.
Above 1000 RPM all is good.
"Felt" like a vaccum leak.
Vaccum at fast idle ...17 PSI steady. Kind of fast drop at the Lope point.
Checked plugs... carboned but not bad, replaced with new, same result,
put old back in.
Checked spark... Healthy 1/4"
Checked ground on distributor by secondary ground... OK
Checked for full voltage to coil + and Pertronics +... OK
Drained gas from marine tank put in fresh..... No love
Checked timing..... Bang on
Problem disapeared...Damn gremlins


Sticking intake valve? but no POP through Carb
Crap in carb that got sucked through?

Damn gremlins

Any thoughts, all are appreciated.

J.B.
Last edited by jbxx on Wed Jan 28, 2009 1:57 pm, edited 1 time in total.
User avatar
jbxx
SGT
SGT
Posts: 193
Joined: Sat Oct 20, 2007 5:53 am
Location: Mill Valley

Missing piece of info

Post by jbxx »

The idle adjustment screw has never had any effect from seated to
just before it falls out to never be found again in the snow ( joke).
When removed there is a noticeable vaccum leak that when my finger
covers hole, goes away. So I'm assuming that the path from the needle valve to the venturi <sp?> is good, maybe a blockage above the valve. BUT, needle valve has never had any effect, even before idle problem.
J.B.
Cal_Gary
Moderator
Moderator
Posts: 4242
Joined: Mon Oct 22, 2007 5:51 am
Location: Draper, Utah

Post by Cal_Gary »

If you get no changes when turning the needle valve a number of turns there has to be something amiss inside. I needed to dial mine in once I replaced the carb, and turning it out allowed it to run richer which solved the problem.
Gary
Cal_Gary
1954 M37 W/W
MVPA Correspondent #28500
Dicktater
CPL
CPL
Posts: 102
Joined: Mon Oct 22, 2007 4:36 am
Location: Southern Indiana

Post by Dicktater »

Float Stuck? or Maybe carb freezing up ? Quick changes in ambient Temp and Humidity can cause Carb to grow ice on the carb body.
MSeriesRebuild
1SG
1SG
Posts: 2832
Joined: Sat Oct 20, 2007 4:35 am
Location: Norwood, NC
Contact:

Re: Missing piece of info

Post by MSeriesRebuild »

jbxx wrote:The idle adjustment screw has never had any effect from seated to
just before it falls out to never be found again in the snow ( joke).
When removed there is a noticeable vaccum leak that when my finger
covers hole, goes away. So I'm assuming that the path from the needle valve to the venturi <sp?> is good, maybe a blockage above the valve. BUT, needle valve has never had any effect, even before idle problem.
J.B.
Internal carb problems is your deal. Most likely you need to fully disassemble removing all the passage plugs for a good rodding, soaking in a good carb cleaning solution, & blowing out thoroughly. Build up using a new rebuild kit. This will fix you up more than likely unless you are able to spot other internal issues along the way.
Charles Talbert
www.mseriesrebuild.com
User avatar
jbxx
SGT
SGT
Posts: 193
Joined: Sat Oct 20, 2007 5:53 am
Location: Mill Valley

Post by jbxx »

I seem to remember that you liked the Snake River
rebuild kit. Was that correct?
J.B.
MSeriesRebuild
1SG
1SG
Posts: 2832
Joined: Sat Oct 20, 2007 4:35 am
Location: Norwood, NC
Contact:

Post by MSeriesRebuild »

jbxx wrote:I seem to remember that you liked the Snake River
rebuild kit. Was that correct?
J.B.
Yes I am fond of the kits Tom offers, good quality at a good price.
Charles Talbert
www.mseriesrebuild.com
Post Reply