mikuni on TLR200

weldingrod · 09-14-2012, 09:23 PM

Hi guy's,
bought a Tlr200 a while back and it came fitted with a mikuni copy(pz22....but outlet side is acctualy 26mm ).Long and short of it is I now have it running great from tickover to 3/4 throttle....then stutters, making me think main jet not right....but plug looks chocky brown at chop. It will pull full throttle from low revs, but when revs get high it stutters. So, my question is, maybe it's not the main jet, but rev limiter or just plain crap cdi ignition curve? I have heard a pit bike cdi is an improvement....but which one? Could also be the airbox which has a nasty kink in the standard inlet rubber tube which hooks on to the carbie...this might be ok with standard keihin shit performance carb, but not suiting the Mikuni?. Made a less restrictive muffler as I thought maybe it was choking it...but no difference. Any advice most welcome......been trying to down load some pictures, but didn't work....well it kinda did.

lineaway · 09-15-2012, 06:24 AM

Did you ever read this?
http://www.trialscentral.com/forums/...-at-high-revs/
Air flow can be quite the problem, I know you have the real tlr. Good luck.

weldingrod · 09-15-2012, 10:53 PM

thanks bud, i have seen that....I am bashplate on that channel, but I couldn't use that handle on ADV as someone else was already using it.
to add to the report on my TLR, have checked the cam timing and valve clearances....all spot on, also tried hotter and cooler plugs....no difference.the standard airbox had no snorkle and I opened up the inlet hole in the top of the boxto let more air in, jets in the mikuni are 20 pilot and 95 main. the 95 mikuni is equivalent to 105 keihin, so maybe still a little rich???but from the amount of stuttering I would have expected the plug to be sooty(megga rich) but it's not. this was what made me think it may be the ignition side which wasn't up to scratch.

Pete-NZ · 09-16-2012, 12:24 AM

TL 200 OKO carbs
http://www.mid-atlantictrials.com/Sales.html

weldingrod · 09-16-2012, 01:22 AM

Thanks Pete. Interesting the 24mm OKO carb for the TLR....they junk the airbox and put a UNI-filter on. This is something I have been thinking of trying, as I have a UNI-filter on my XL200 trials special...and it works very well on that.

Twin-shocker · 09-16-2012, 02:55 AM

The firetrap gauze is what restricts the stock TLR air box, and its easy enough to remove this and fit a foam filter inside the stock air box. Do not remove the stock air box, as bikes will not run as well without this.

However as it looks like you have a low volume/restrictive exhaust system on your bike, before anything get that sorted out, as the TLR never runs well without a good exhaust.

weldingrod · 09-16-2012, 03:54 AM

thanks for that twin shock.....will try the air filter mod. the muffler is small volume but straight through so shouldn't be restricting the motor.

Twin-shocker · 09-16-2012, 09:31 AM

You will find you have a lot more torque if you can find a large volume straight through exhaust. Remove the flame trap inside the stock air box, and you should find a foam spigot mount filter which will fit the stock air box, and then you simply need to make a spigot and fit it the air intake to attach the new filter to.

weldingrod · 09-16-2012, 02:56 PM

thanks for the ideas twinshock....will try them out

weldingrod · 09-23-2012, 01:55 AM

ok folks, took the filter and flame trap out of the air box but left the airbox on. I had already opened up the top to let more air in, so just covered that with alloy mesh and some filter foam to filter the air as it entered the airbox. went and did some sections and the bike performed as before and when given wide open throttle, got exactly the same result as before. so this would suggest that lack of air flow is not the problem. here's some pictures.

weldingrod · 09-23-2012, 01:56 AM

Twin-shocker · 09-23-2012, 03:43 AM

You will find power is reduced by cutting the top of the air box. All that is required here is to leave the top standard and drill a couple of 16mm holes.

However unless your exhaust is working properly you will find it very difficult to get a TLR running properly, and altering the intake isnt going to make that much difference to how it runs.

weldingrod · 09-23-2012, 05:35 PM

Yeh, thought I would try the airfilter first as it was easy....fabricating a new exhaust set up is going to take a while. Cheers.

twinjet · 09-25-2012, 12:38 PM

Run the bike up a hill with the throttle wide open and slowly apply the choke. If it runs better wide open with the choke on, the mainjet is to lean.

weldingrod · 09-25-2012, 09:54 PM

Thanks Twin jet, will give that ago. Believe it or not....your the second person today that put that idea forward.

09-14-2012, 09:23 PM	#1
weldingrod ^OP Adventurer Joined: Sep 2012 Oddometer: 35	mikuni on TLR200 *Hi guy's,* bought a Tlr200 a while back and it came fitted with a mikuni copy(pz22....but outlet side is acctualy 26mm ).Long and short of it is I now have it running great from tickover to 3/4 throttle....then stutters, making me think main jet not right....but plug looks chocky brown at chop. It will pull full throttle from low revs, but when revs get high it stutters. So, my question is, maybe it's not the main jet, but rev limiter or just plain crap cdi ignition curve? I have heard a pit bike cdi is an improvement....but which one? Could also be the airbox which has a nasty kink in the standard inlet rubber tube which hooks on to the carbie...this might be ok with standard keihin shit performance carb, but not suiting the Mikuni?. Made a less restrictive muffler as I thought maybe it was choking it...but no difference. Any advice most welcome......been trying to down load some pictures, but didn't work....well it kinda did. weldingrod screwed with this post 09-14-2012 at 09:57 PM Reason: pictures

09-16-2012, 12:24 AM	#4
Pete-NZ Studly Adventurer Joined: May 2011 Oddometer: 508	TL 200 OKO carbs http://www.mid-atlantictrials.com/Sales.html __________________ Here.... my XR250 leaner side car build http://www.advrider.com/forums/showthread.php?t=716993

09-25-2012, 12:38 PM	#14
twinjet Gnarly Adventurer Joined: Apr 2009 Location: NH Oddometer: 303	Choke test Run the bike up a hill with the throttle wide open and slowly apply the choke. If it runs better wide open with the choke on, the mainjet is to lean. __________________ 2004 KLR650

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09-15-2012, 06:24 AM	#2
lineaway Studly Adventurer Joined: Oct 2011 Location: nm Oddometer: 774	Did you ever read this? http://www.trialscentral.com/forums/...-at-high-revs/ Air flow can be quite the problem, I know you have the real tlr. Good luck.

09-15-2012, 10:53 PM	#3
weldingrod ^OP Adventurer Joined: Sep 2012 Oddometer: 35	*thanks bud, i have seen that....I am bashplate on that channel, but I couldn't use that handle on ADV as someone else was already using it.* to add to the report on my TLR, have checked the cam timing and valve clearances....all spot on, also tried hotter and cooler plugs....no difference.the standard airbox had no snorkle and I opened up the inlet hole in the top of the boxto let more air in, jets in the mikuni are 20 pilot and 95 main. the 95 mikuni is equivalent to 105 keihin, so maybe still a little rich???but from the amount of stuttering I would have expected the plug to be sooty(megga rich) but it's not. this was what made me think it may be the ignition side which wasn't up to scratch.

09-16-2012, 01:22 AM	#5
weldingrod ^OP Adventurer Joined: Sep 2012 Oddometer: 35	Thanks Pete. Interesting the 24mm OKO carb for the TLR....they junk the airbox and put a UNI-filter on. This is something I have been thinking of trying, as I have a UNI-filter on my XL200 trials special...and it works very well on that.

09-16-2012, 02:55 AM	#6
Twin-shocker Studly Adventurer Joined: Jan 2012 Oddometer: 993	The firetrap gauze is what restricts the stock TLR air box, and its easy enough to remove this and fit a foam filter inside the stock air box. Do not remove the stock air box, as bikes will not run as well without this. However as it looks like you have a low volume/restrictive exhaust system on your bike, before anything get that sorted out, as the TLR never runs well without a good exhaust.

09-16-2012, 03:54 AM	#7
weldingrod ^OP Adventurer Joined: Sep 2012 Oddometer: 35	thanks for that twin shock.....will try the air filter mod. the muffler is small volume but straight through so shouldn't be restricting the motor.

09-16-2012, 09:31 AM	#8
Twin-shocker Studly Adventurer Joined: Jan 2012 Oddometer: 993	You will find you have a lot more torque if you can find a large volume straight through exhaust. Remove the flame trap inside the stock air box, and you should find a foam spigot mount filter which will fit the stock air box, and then you simply need to make a spigot and fit it the air intake to attach the new filter to.

09-16-2012, 02:56 PM	#9
weldingrod ^OP Adventurer Joined: Sep 2012 Oddometer: 35	thanks for the ideas twinshock....will try them out

09-23-2012, 01:55 AM	#10
weldingrod ^OP Adventurer Joined: Sep 2012 Oddometer: 35	ok folks, took the filter and flame trap out of the air box but left the airbox on. I had already opened up the top to let more air in, so just covered that with alloy mesh and some filter foam to filter the air as it entered the airbox. went and did some sections and the bike performed as before and when given wide open throttle, got exactly the same result as before. so this would suggest that lack of air flow is not the problem. here's some pictures.

09-23-2012, 01:56 AM	#11
weldingrod ^OP Adventurer Joined: Sep 2012 Oddometer: 35

09-23-2012, 03:43 AM	#12
Twin-shocker Studly Adventurer Joined: Jan 2012 Oddometer: 993	You will find power is reduced by cutting the top of the air box. All that is required here is to leave the top standard and drill a couple of 16mm holes. However unless your exhaust is working properly you will find it very difficult to get a TLR running properly, and altering the intake isnt going to make that much difference to how it runs.

09-23-2012, 05:35 PM	#13
weldingrod ^OP Adventurer Joined: Sep 2012 Oddometer: 35	*Yeh, thought I would try the airfilter first as it was easy....fabricating a new exhaust set up is going to take a while. Cheers.*

09-25-2012, 09:54 PM	#15
weldingrod ^OP Adventurer Joined: Sep 2012 Oddometer: 35	*Thanks Twin jet, will give that ago. Believe it or not....your the second person today that put that idea forward.*