New MK2 owner in need of help

[MFerioli]

Thanks knackered, I actually came across that post already while doing some searching.

I made a little throttle position gauge today and went for a ride. I was surprised how little throttle I actually use while on the road here, I barely get to quarter open. It seems as though it starts to run really sputtery after about one eigth open to one quarter open when it first or second. But when in third or fourth at about the same speed it's smoother. Not sure what load has to do with with this issue.

So after about eigth open it sounds sputtery and doesn't have much power. I can get it going fast though, but it doesn't sound smooth or feel smooth through most of the acceleration. It was also pretty smoky while sitting at some lights, it wasn't having that problem before. It did richen the mixture screw about one quarter turn from factory and moved the needle up by one notch.

Where are the crank seals that could be causing this? Does the case need to be split to replace them?

Why would the whole combustion chamber be clean but the plug be oily?

[MFerioli]

http://s262.photobucket.com/albums/ii12 ... 0RM%20MK2/

here are some photos to go along with this post. I took a shot of the generator side to show that no seals are leaking oil out on that side, not sure if that eliminates those seals as a potential problem. Is that side where I could potentially have a crank seal air leak??

[knackeredMk1]

I would try out a few things before you commit to changing the seals but you don't have to split the crank.

From what you have said you raised the needle in the slide by one notch. I think you should try dropping it two notches and see if that inproves things. Also set you air screw. - You need to get the engine warm and 'cleaned through'. Then set at idle you need to adjust the air screw until you get the revs to a maximum whilst idling. You may have to adjust the idle screw after doing this.

[knackeredMk1]

I would try out a few things before you commit to changing the seals but you don't have to split the crank.

From what you have said you raised the needle in the slide by one notch. I think you should try dropping it two notches and see if that inproves things. Also set you air screw. - You need to get the engine warm and 'cleaned through'. Then set at idle you need to adjust the air screw until you get the revs to a maximum whilst idling. You may have to adjust the idle screw after doing this.

[MFerioli]

Thanks knackered.

Your comment about proper air screw adjustment got me reading a lot more on that subject and has me pretty convinced that I probably will be able to solve this with adjustment and or jets. I'll let you know how the air screw adjustment goes.

[fallenmikethebike]

I would try out a few things before you commit to changing the seals but you don't have to split the crank.

From what you have said you raised the needle in the slide by one notch. I think you should try dropping it two notches and see if that inproves things. Also set you air screw. - You need to get the engine warm and 'cleaned through'. Then set at idle you need to adjust the air screw until you get the revs to a maximum whilst idling. You may have to adjust the idle screw after doing this.

+1, it does sound like it's running very rich, check the filter for cleanliness, is the exhaust blocked? or needing a de-coke?
Put a new cheap plug in and do a plug chop test.
Mike

[back off road]

+1, it does sound like it's running very rich, check the filter for cleanliness, is the exhaust blocked? or needing a de-coke?
Put a new cheap plug in and do a plug chop test.
Mike

thats all you ever put in isnt it mike

[MFerioli]

i don't think there is a cheap part in all of japan.

[fallenmikethebike]

+1, it does sound like it's running very rich, check the filter for cleanliness, is the exhaust blocked? or needing a de-coke?
Put a new cheap plug in and do a plug chop test.
Mike

thats all you ever put in isnt it mike [/quote

Frugality if an expensive plug made the bike run twice as well I might invest however, this is not the case.
Mike

[njhardy]

+1 Mike.
Hi MFerioli- Luckily Japan has pretty much all the spares you will ever need (even if they are expensive). Your first task is to get the correct mixture setting and oil setting. -If you find this does not work, then you know that it's probably something else (like a seal leak).
Do a plug chop with a clean plug and go for a little ride and open up the throttle to at least half or more- ride for at least 1 km. Stop immediately & take out the plug and check its state. Is it oily? -Too much oil from the pump, so wind the cable down on the pump a bit & try again. Is it black from a rich mixture? Then lean up the mixture a bit. It should be dark biscuit brown and blue tinge to the exhaust smoke when running, not clouds. If you can't adjust the carb needle any more, then go up or down in size with your main jet.
I had loads of issues with mine when I got it, after many years of neglect. Its quite likely you have a few problems here, each one you need to isolate before moving on. Because I live in a very hot climate, I actually had to go down to a 130 main jet and 35 pilot before mine would run properly. After market pipes can make a difference too. Once the mixture and oil is OK, then you can look into other problems with her running smoothly- she should be smoother running than a 4 stroke and far more 'peaky' in power.

[MFerioli]

I went through the proper air screw adjustment technique pretty carefully and found that highest idle was about 2 5/8 turns out. It ran pretty well for about 15 minutes, then turned really bad and I had to sputter my way home, stalling out a bunch at the lights. I went to the mechanic and ordered up some crank seals and various other gaskets so I can pull the reed valve out and take the head off. I hope to get those seals in this weekend and then start the adjustment process over. I figure from what you guys have said about the crank seals, I'd better go ahead and do those first before I start chasing an adjustment ghost.

I'll post back after the seals go in.

Anything I should be aware of before I do that job? Things not to do, or other things to look for while it's apart?

Thanks,
Mike

[mammoth200]

When putting the seal in generator side, be very wary. I pushed a seal all the way through when doing my rebuild and it was an absolute arse to get back out, and I destroyed the seal in the process, luckily I ordered 2 on that side!

[MFerioli]

Do you guys know the proper size flywheel puller I need? 24mm x 1.5mm??

1991 mk2

I searched on here but could not find a conclusive answer.

Thanks

[mammoth200]

The one I have has a 27 x 1.00 left hand thread, and a 24 x 1.00 right hand thread on it, very much like this one

http://www.ebay.co.uk/itm/MOTORCYCLE-FL ... 2eb5404465

did the job perfectly, however I can't recall which end I used!

[MFerioli]

Thanks! That was helpful. Hopefully I ordered the right one.