timing help

[Dale Sonnenschein]

I have a 75 250 penton and I'm having a tough time getting it running. It ran with the timing the way it was set when I got it but only by jumping it.The top end is new and it has a new mikuni. I set the timing and it's quite a ways from where it was set when I got it. It will still only jump start. I'm not sure what I am missing about this. Anyone have an idea of what I need to do?

Thanks

Dale

74 puch 175 SD
73 Husky 360 WR/RT
75 Penton 250
10 ktm 250xc
02 bmw r1150r

[wfopete]

How did you go about setting the timing?  Did you use a dial indicator or...?


Pete Petrick
175 Jackpiner
Slow but Good

[Dale Sonnenschein]

Yes but I'm not sure I understand the manual. It shows 2.25mm V OT.
What is V OT? I read it as BTDC in the manual.
Maybe the motoplat is weak? I've seen better spark but I've seen worse too.


74 puch 175 SD
73 Husky 360 WR/RT
75 Penton 250
10 ktm 250xc
02 bmw r1150r

[brian kirby]

quote:Originally posted by Dale Sonnenschein

It ran with the timing the way it was set when I got it but only by jumping it.

CLASSIC symptom of a weak/failing Motoplat. Bad Motoplat, for sure.

Brian

[454MRW]

Also a symptom of a leaking ignition side crank seal is having to always push start the bike. If you are not sure of the seal condition, try squirting a little gas/oil mixture in the spark plug hole, put the plug back in, and then see if it tries to kick start. When the crank seal starts to leak, it causes a weak signal to the carb that won't pull enough fuel mixture into the engine to start easily. Also, the 74 250 HS timing spec, is 2.55 BTDC, which is a little more aggressive than the later 78-80 bikes. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R

[Ernie Phillips]

Also a classic symptom of Mikuni (enrichening circuit instead of true choke or tickler system).  Need to keep throttle completely closed for enrichening circuit to work.

Ernie P.
Chattanooga, TN

[Kip Kern]

If Motoplat, 2.6mm BTDC. Use a Sachs timing tool or similar, you can't miss. Any questions, send the ignition and coil to PVL to be tested and re magnatized. Ask for BJ or Jerry

[Dale Sonnenschein]

THanks Guys, Looks like i have a little work to do.

74 puch 175 SD
73 Husky 360 WR/RT
75 Penton 250
10 ktm 250xc
02 bmw r1150r