Welding magnesium alloy crankcase

[Toleman]

Also the old plug was dark and the new plug which is about two hours old is showing oily deposits which says rich too.

 

[eLuSiVeMiTe]

Get a selection of jets and put it back so stock initially and see how it runs.
X turns on the screw from fully in depending on carb
Take lots of notes as you make changes till you find the sweet spot.
How far did you go with your rebuild. New reeds? Cleaned exhaust system and repacked. Always worthwhile for performance gains.

Plenty of good articles for tuning advice about.

Recommend iridium plugs. Worth the extra pennies. Do a plug chop test if you can for the best idea what the plugs telling you.

Re fuel. Only ever rode with fresh. Just used to grab 2 to 4 litres on route depending on how long I was planning to ride.

Worth turning fuel off and draining the carb when finished till it dies.

Talking of fuel. Don't skimp. Premium from the big names is worthwhile.

 

[Toleman]

Cheers mate I’ll give all that I try. Not planning on keeping it when I get the 250/ 300 exc so didn’t want to spend too much on things but they have been done if required.

The plug is a decent ngk one £20 odd which has a special tip that doesn’t break off and ruin the cylinder, piston and head. The previous owner put a hotter plug in than recommended which is maybe why it ran a little better than now being too rich

Fuel I buy shell standard which is 97.

I had it from my brother in law for cheap, I only paid £750 as he wanted rid of it. It’s had a new clutch basket and clutch kit on it and it was rebuilt before he had it. It’s got about 25 hours on now. I’ve got no idea what it’s worth as it’s not new and not a classic so falls in the middle somewhere. I’d like to think I could break even on it (purchase cost plus parts) which I won’t do spending lots of money on it. I would like it running well though.

I’ve already been looking at exhausts on the ktm’s. fmf shorty pipes sound awesome on the 2t.

 

[Popcorn]

That second video was before I was born, just. “They’ve gone to a disc brake system”

Hell of a skill in that trials malarkey.

Had a little blast up the runway and the jetting all seems to be out. It was a bit smokey previously but ran pretty good, I’m surprised as it’s really cold today so you would think the denser air would leen the mix a bit.

Colder dense air means there is more oxygen in the charge, hence the weaker mixture.

 

[Toleman]

Would that not be a positive over the mix that’s currently too lean?

It started with no choke yesterday which shows how rich it is.

 

[dobbslc]

Did you replace the crank seals when you rebuilt it?

 

[Toleman]

No I got some more but the others were brass rimmed and punched in and I was already wrecking parts - didn’t fancy doing any more damage. Do you think it’s burning gear oil then?

 

[dobbslc]

It could be, I had it on an old RD 250 that never ran right, I sold it as I couldn't be arsed to strip it down. Worth a few quid now!

 

[Toleman]

I’ve taken the main jet out and it’s #178. Can’t seem to find anything close to that. There’s kits on eBay which most go up to 160 and very few upto 170

Where do you think I should start?

 

[Toleman]

Forget that I’ve found them. I’ll order some smaller ones and let you know how I get on.

 

[eLuSiVeMiTe]

Forget that I’ve found them. I’ll order some smaller ones and let you know how I get on.

Never tuned a mx mate. Only trials. Sure someone could help.

 

[Toleman]

178 - 176 vast improvement.

Going to try a 174 tomorrow