Magician Running Funny

[_skid87]

I had about 60 miles on the bike tonight and decided to ride it into town, about 8 miles one way. About half way there I notice it running a little funny. Best I can describe it is a surge. Riding at a constant speed it would randomly bog a little for a second every few seconds. I was WOT. All I have done to the carb is adjust the mixture screw out to 2 turns and shimmed with a couple washers. I figured it was close to right as I can hit 65+mph on flat ground and sometimes 70 downhill. Suggestions? Have not checked valve clearance yet and know I need to. It's still cold blooded but not hard to start when hot....

[Megadan]

No increase on the main jet? Also, yes, adjust the valves.

[_skid87]

Originally Posted by Megadan

No increase on the main jet? Also, yes, adjust the valves.

When I was in the carb I had not received my jet kit yet. I have it now. What should I go with?

[Megadan]

Originally Posted by _skid87

When I was in the carb I had not received my jet kit yet. I have it now. What should I go with?

Any mods done to the bike? I am not sure what jets you have, but at least a 105 main jet if the bike is stock.

[_skid87]

Originally Posted by Megadan

Any mods done to the bike? I am not sure what jets you have, but at least a 105 main jet if the bike is stock.

It is completely stock

[Megadan]

Originally Posted by _skid87

It is completely stock

Yeah, I would toss at least 105 main jet in it then. If you live close to sea level a 110 may be needed. No matter what, it will be way better than the stock main jet.

[_skid87]

Originally Posted by Megadan

Yeah, I would toss at least 105 main jet in it then. If you live close to sea level a 110 may be needed. No matter what, it will be way better than the stock main jet.

I set my valves at .004mm.

I found out the 100 main was what I needed. The 110 was just to much. The factory 98 was closer than the 110. I skipped trying the 105 and stuck the 100 in and it's perfect. I did two washers on the needle, 1.75 turns out on mixture screw and it runs great. Flat land speedo shows 65 maxed out no more sputtering or surging.

[Wild Dog]

Originally Posted by _skid87

I set my valves at .004mm.

Are you sure that you are using mm and not "??? If you are using metric, then go and reset the valves, because that's below the minimium which in metric is 0.05mm

Down the road the safest lash is the one that most people use here which is .003" intake and .004"

[Megadan]

I am assuming he meant .004 inches. I have a pretty extensive feeler gauge collection, but even I don't have a 4 micron thick feeler gauge. Either that or he mean .04mm and added an extra zero. .04mm would actually be too tight. .05mm/.002" is the minimum gap tolerance.

[NzBrakelathes]

Originally Posted by _skid87

I set my valves at .004mm.

I found out the 100 main was what I needed. The 110 was just to much. The factory 98 was closer than the 110. I skipped trying the 105 and stuck the 100 in and it's perfect. I did two washers on the needle, 1.75 turns out on mixture screw and it runs great. Flat land speedo shows 65 maxed out no more sputtering or surging.

You may like to check out my eBay store for the "first tune kit" this will help you tune the carb and has other good fist set up parts too.
The other is the valve adj set with metric gauges and the special spanner.
Also I suggest the "Go no Go" method

[_skid87]

Originally Posted by NzBrakelathes

You may like to check out my eBay store for the "first tune kit" this will help you tune the carb and has other good fist set up parts too.
The other is the valve adj set with metric gauges and the special spanner.
Also I suggest the "Go no Go" method

Yeah it's .038mm my bad... I'm not buying some special kit on the slow boat from China when I need to do them now.

[Megadan]

Originally Posted by _skid87

Yeah it's .038mm my bad... I'm not buying some special kit on the slow boat from China when I need to do them now.

I would suggest setting them to .05mm or .002in. Any smaller than that is considered out of spec on these motors.

All of that without a sales pitch too. Amazing.

[OneLeggedRider]

Don't listen to them, they're all wrong. Hahaha!

A good rule of thumb for any small motor is .003" intake and .004" on the exhaust. It's a safe bet and will perform well. I might take mine a little tighter, maybe .002" and .003" now that it's broke in just to try and squeeze every bit of performance out of it. But I also know what "slight drag" on the feeler gauge is, some dont.

Damn, I forgot to include my sales pitch..

[Megadan]

Originally Posted by OneLeggedRider

Don't listen to them, they're all wrong. Hahaha!

A good rule of thumb for any small motor is .003" intake and .004" on the exhaust. It's a safe bet and will perform well. I might take mine a little tighter, maybe .002" and .003" now that it's broke in just to try and squeeze every bit of performance out of it. But I also know what "slight drag" on the feeler gauge is, some dont.

Damn, I forgot to include my sales pitch..

Want to be obsessive compulsive with lash? I can zero my Mituboyo 0 -.030" dial indicator using my clamp base and literally measure the back lash of the adjuster. It measures in .0006" increments. It would be a lot of work, but a lot harder to screw up lol.

Buy one now!

[NzBrakelathes]

Originally Posted by OneLeggedRider

Don't listen to them, they're all wrong. Hahaha!

A good rule of thumb for any small motor is .003" intake and .004" on the exhaust. It's a safe bet and will perform well. I might take mine a little tighter, maybe .002" and .003" now that it's broke in just to try and squeeze every bit of performance out of it. But I also know what "slight drag" on the feeler gauge is, some dont.

Damn, I forgot to include my sales pitch..

I would agree with that! and here's the sales pitch:

https://www.ebay.com/itm/303077495104

https://www.ebay.com/itm/303067563984

These might suit to solve your/his/the issues (skills required)