200 Beast + Mikuni carb= Joy! - Page 5

Weldangrind · 11-15-2009, 09:53 PM

Stew, your tendonitis won't feel any better after trying to remove the intake tube.

You can get a gear wrench on the upper bolt (8mm), but the bottom will only accept a box end wrench and will only give you about 1/8 of a turn at a time. You don't need to remove the carb from the intake tube though, so that's a bonus.

I recommend lotsa Ibuprofen.

PCD · 11-15-2009, 09:54 PM

Quote:

Originally Posted by MICRider

Lol, I took the Beast out for a little honk tonight... Not sure if I had it fully warmed up or not (don't really think I did), it ran better but still not up to snuff. Bummer! So, I think I will be checking that intake for leaks and maybe cranking the mixture screw out another half or quarter turn. It's funny though, it will run really good, then start missing, farting, stalling... Definitely going to check the intake! Tis funny too, cause my sons 110 Mini-Beast, once warmed up runs flawlessly! Too bad my Beasty aint the same, but gives me something to play with I guess

. Tendonitis in my wrist has flared up again, so I cant really take it out for a proper ride anyway. Supposed to be nice for a few days here so I will try to get some more wrenching done on it in the evenings... Though no mods for me, just trying to get it to run right!

Regards,
Stew

Check the plug...takes 2 minutes. If that plug is dark at all crank that A/F screw out another half turn. Trust me, please.

W&G...my birthday is April 22/58...that should clarify matters

, but thatnks for the benefit of the doubt...always said you were a classy guy.

waynev · 11-15-2009, 10:00 PM

PCD, did you mean if the plug is dark to lean out the A/F mixture?, to lean the mixture wouldn't you have to screw in and not out ?

PCD · 11-15-2009, 10:04 PM

Quote:

Originally Posted by waynev

PCD, did you mean if the plug is dark to lean out the A/F mixture?, to lean the mixture wouldn't you have to screw in and not out ?

No.

Our Mikunis A/F screw is an AIR screw as opposed to other Mikunis with the screw at the front (or back, I forget now) which is a fuel screw.

If you read that link waynev posted it explains things nicely. Anyway, on MY Mikuni that bottom screw controls AIR, not fuel. Its exactly the reverse to what you are thinking.

waynev · 11-15-2009, 10:08 PM

Actually on my link i posted you will see that our A/F valve is at the front of the carb so that is fuel, the ones on my snowmobile were on the back which is air.

when the carb is on the bike that screw is closer to the front, the filter goes on the back.

PCD · 11-15-2009, 10:12 PM

Quote:

Originally Posted by waynev

Actually on my link i posted you will see that our A/F valve is at the front of the carb so that is fuel, the ones on my snowmobile were on the back which is air.

when the carb is on the bike that screw is closer to the front, the filter goes on the back.

I gotta remember to get under the bike on the SAME SIDE every time. Messes me up constantly.

waynev · 11-15-2009, 10:17 PM

Just wanted to make it clear.

If the screw is closer to the air filter than it's an AIR screw ( out is leaner) , if it closer to the manifold then it's a FUEL screw ( out is richer).

Weldangrind · 11-15-2009, 10:21 PM

Quote:

Originally Posted by waynev

Just wanted to make it clear.

If the screw is closer to the air filter than it's an AIR screw ( out is leaner) , if it closer to the manifold then it's a FUEL screw ( out is richer).

If we could somehow place this comment under the forum name in bold, we'd all be better off. I don't know why I can't get it through my thick skull.

waynev · 11-15-2009, 10:26 PM

Not a bad idea W&G, personally it's etched in my mind as i've been playing with mikuni's for 25 of my 39 years.

Weldangrind · 11-15-2009, 10:33 PM

For those who can't walk in to a local bike shop and buy Mikuni jets, nichesupply on eBay has a decent selection of main and pilot jets at a fair price. By comparison, I paid $5.00 each for mains and pilots over the counter.

PCD · 11-15-2009, 10:35 PM

Back to MICRider...my mechanical information was wrong, but the point of my post remains the same.

Leaning my Mikuni out made a huge difference. When it was rich I had a hard time starting (not insane, just harder than it should of been) and high speed breakup.

I leaned it out till I hit tan on the plug and tan on the funny little saltshaker baffle plate inside the Monster exhaust, now its perfect.

My apologies for getting things mixed up, glad I was straightened out, but I stand behind my original point.

Weldangrind · 11-15-2009, 10:39 PM

For further clarification when searching for Mikuni PZ30 jets, look for vm28/486 (pilot jet) and N100.604 (main jet). These guys have it figured out: http://www.carbparts.com/mikuni/mikuni_tuning.htm#Pilot Jets

MICRider · 11-15-2009, 10:54 PM

Lol, I understand what you all were getting at, if the plug is dark, crank the mixture screw in a quarter or half turn as that would be making it leaner, if the plug is too light crank it out a bit to richen it... I will definitely have to check that out. Funny things are though:
1) It lights right up... Give it a choke when cold and it doesn't even turn over once before it starts.
2) It idles beautifully, smooth and not too fast
3) Will run perfect for a few hundred yards going through the gears

Then it starts to stumble like it is not getting gas or something... Could that possibly be an intake leak or maybe something simpler like a collapsing fuel line? I never did replace the lines like the rest of you guys did and they are an awful soft line. Tricky to diagnose when it runs so well for a bit, then chokes. An intake leak would make it starve all the time yes? I will have to check a few things tomorrow when I get home from work. (and its warmer!)

Regards,
Stew

Weldangrind · 11-15-2009, 10:59 PM

Maybe your fuel filter is clogged Stew. BTW, snowmobile fuel line is a good choice for cold climates (it's transparent too).

PCD · 11-15-2009, 11:00 PM

You're bang on. If it were a pinched line it would most likely stay pinched all the time.
I'm going to ask you a silly question...you do shut the choke off right?
Other than that I would say its something changing with the engine afterr its warmed up.

11-15-2009, 09:53 PM	#61
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Stew, your tendonitis won't feel any better after trying to remove the intake tube. You can get a gear wrench on the upper bolt (8mm), but the bottom will only accept a box end wrench and will only give you about 1/8 of a turn at a time. You don't need to remove the carb from the intake tube though, so that's a bonus. I recommend lotsa Ibuprofen. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

11-15-2009, 10:33 PM	#70
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	For those who can't walk in to a local bike shop and buy Mikuni jets, nichesupply on eBay has a decent selection of main and pilot jets at a fair price. By comparison, I paid $5.00 each for mains and pilots over the counter. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

11-15-2009, 10:35 PM	#71
PCD Join Date: Oct 2009 Location: Newmarket On Canada Posts: 382	Back to MICRider...my mechanical information was wrong, but the point of my post remains the same. Leaning my Mikuni out made a huge difference. When it was rich I had a hard time starting (not insane, just harder than it should of been) and high speed breakup. I leaned it out till I hit tan on the plug and tan on the funny little saltshaker baffle plate inside the Monster exhaust, now its perfect. My apologies for getting things mixed up, glad I was straightened out, but I stand behind my original point. __________________ Good, Fast, or Cheap....Pick Two.
	0

11-15-2009, 10:39 PM	#72
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	For further clarification when searching for Mikuni PZ30 jets, look for vm28/486 (pilot jet) and N100.604 (main jet). These guys have it figured out: http://www.carbparts.com/mikuni/mikuni_tuning.htm#Pilot Jets __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

11-15-2009, 10:59 PM	#74
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Maybe your fuel filter is clogged Stew. BTW, snowmobile fuel line is a good choice for cold climates (it's transparent too). __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

11-15-2009, 10:00 PM	#63
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	PCD, did you mean if the plug is dark to lean out the A/F mixture?, to lean the mixture wouldn't you have to screw in and not out ?
	0

11-15-2009, 10:08 PM	#65
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	Actually on my link i posted you will see that our A/F valve is at the front of the carb so that is fuel, the ones on my snowmobile were on the back which is air. when the carb is on the bike that screw is closer to the front, the filter goes on the back.
	0

11-15-2009, 10:17 PM	#67
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	Just wanted to make it clear. If the screw is closer to the air filter than it's an AIR screw ( out is leaner) , if it closer to the manifold then it's a FUEL screw ( out is richer).
	0

11-15-2009, 10:26 PM	#69
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	Not a bad idea W&G, personally it's etched in my mind as i've been playing with mikuni's for 25 of my 39 years.
	0

11-15-2009, 10:54 PM	#73
MICRider Join Date: Oct 2009 Location: Alberta, Canada Posts: 3,274	Lol, I understand what you all were getting at, if the plug is dark, crank the mixture screw in a quarter or half turn as that would be making it leaner, if the plug is too light crank it out a bit to richen it... I will definitely have to check that out. Funny things are though: 1) It lights right up... Give it a choke when cold and it doesn't even turn over once before it starts. 2) It idles beautifully, smooth and not too fast 3) Will run perfect for a few hundred yards going through the gears Then it starts to stumble like it is not getting gas or something... Could that possibly be an intake leak or maybe something simpler like a collapsing fuel line? I never did replace the lines like the rest of you guys did and they are an awful soft line. Tricky to diagnose when it runs so well for a bit, then chokes. An intake leak would make it starve all the time yes? I will have to check a few things tomorrow when I get home from work. (and its warmer!) Regards, Stew
	0

11-15-2009, 11:00 PM	#75
PCD Join Date: Oct 2009 Location: Newmarket On Canada Posts: 382	You're bang on. If it were a pinched line it would most likely stay pinched all the time. I'm going to ask you a silly question...you do shut the choke off right? Other than that I would say its something changing with the engine afterr its warmed up. __________________ Good, Fast, or Cheap....Pick Two.
	0