Bultaco sherpa 250

[doggone]

So... we have been given this as 'running five years ago'.
Having been built up from parts in a box by previous owner
But it won't start.
After cleaning points there's a good spark and it should be timed right.
Carb seems to be getting fuel and plug gets wet with fuel - when it doesn't start after prolonged turning over by running down a steep hill.
Two strokes are known to be temperamental but would have hoped to get a few pops and bangs even if it wouldn't run properly.
We have heard crankase seals can go and that will make it not run at all.
Is this next thing to be checking.
Had carb apart to clean out and it was surprisingly good in there TBH.
I'm guessing its from about 1980 but has the look of being cared for e.g. grease on things like chain...

[doggone]

The engine kill on bars has been accidentally mashed, there is just a wire to hold against bars to stop it - we think.
Surely that doesn't work the other way round like needs to be earthed to run.

[stinkwheel]

[doggone]

[A100man]

Like Stinkers mentioned..
I'd go with weak spark (plugs, points condensor, coil - change 'em all)
and/or poorly timed.. I'd expect it to run even with bad seals - although it might not be able to pull the skin off a rice puddin'.
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[ZebraDriver]

I had one of those back in the 80's. Bought it as a non runner. Spent ages trying to get it to start. Eventually heated the barrel with a blowtorch and got my kid brother to push me to bump start it (4th gear). When it did start I found out (the hard way) that the throttle cable had been replaced with one that was too short and was holding the throttle 3/4 open...... Worst bit was that the kill switch was an old Lucas car light switch and it was mounted in the middle of the handlebars.

ZD

[blurredman]

Have you actually verified timing yourself?
____________________
CBT: 12/06/10, Theory: 22/09/10, Module 1: 09/11/10, Module 2: 19/01/11
Past: 1991 Honda CG125BR-J, 1992 (1980) Honda XL125S, 1996 Kawasaki GPZ500S, 1979 MZ TS150.
Current: 1973 MZ ES250/2 - 18k, 1979 Suzuki TS185ER - 10k, 1981 Honda CX500B - 91k, 1987 MZ ETZ250 (295cc) - 40k, 1989 MZ ETZ251 - 51k.

[doggone]

[doggone]

Had it running this morning, I got new plug for it but carb has been in an ultrasonic cleaner.
After about ten minutes it was pretty hot but running then after stopping it would not start again.
At least we know it does run.

[doggone]

It was still proving temperamental to start from cold but it appears the choke was not working.
It has an amal mk2 concentric carb.
The choke doesn't work by restricting air but gives a richer mixture by drawing additional fuel through a fine jet when you operate the lever.
The jet is hidden in a thin channel that draws from bottom of float bowl, and it was blocked at the L shaped bit at very bottom.

With hindsight once we had spark and timing something like, the lack of choke could have been the main problem.

Once that was cleared and reassembled it has been starting first kick and not a lot of effort needed either.
So a quite usable bike for very little money - however now it is running OK we need new rear mudguard (plastic), brake shoes for rear and hose to airbox (it has been running without for testing).
The rear wheel has some loose spokes we might be able to improve things ourselves rather than sending it off with any luck.
Probably around £150 to sort it out.

https://www.inmotiontrials.com/ seem to be a good source of most parts if not always cheapest.

[A100man]

[stinkwheel]

The only good thing about a mk2 concentric is that it isn't a mk1 concentric.

Have a look on feked.com for parts too.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.