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XR200R carb on a TLR200 engine?

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Just rebuilt a tlr engine and installed it in a 2000 xr200. Used the xr200 head and piston, but retained the tlr cam. Installed the xr200r carb, but it pops and snorts, then fouls the plug (x2).

Can the 200 carb be rejetted inexpensively or is it better to get an xr100 carb and jet it?

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Just rebuilt a tlr engine and installed it in a 2000 xr200. Used the xr200 head and piston, but retained the tlr cam. Installed the xr200r carb, but it pops and snorts, then fouls the plug (x2).

Can the 200 carb be rejetted inexpensively or is it better to get an xr100 carb and jet it?

XR100 carb is a bit drastic. But a smaller carb works better on a trials bike. Might consider trying a cheap chinese honda knock off from ebay.

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The quick fix is to install the XR cam, then all of the top end parts will be compatible making it easier to sort out any carb issues. I've often thought that a XR200R top end was just what the anemic TLR needed. I have a TLR bottom end that I bought for a project and the TLR rotor is 21oz heavier than the XR200R rotor, that extra weight would really smooth out the XR bottom end.

Are you using the TLR or XR ignition systems? The XR uses a mechanical ignition advance with none in the CDI box, the TLR is all electronic with the ignition advance in the CDI box; mix and match won't work. The XR CDI box with the TLR sensor will provide zero ignition advance and could be causing your problem.

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Chuck-

I'm using the wiring from the tlr.

With a fresh plug it runs and pulls great. After a couple minutes the engine sputters around 3,000 rpm. Feels like hitting a rev limiter. Pull the plug and it's sooty black. :thumbsup:

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Sounds like part throttle richness which can be caused by a lot of things; dirty air cleaner, high float level, wrong needle clip position, etc.

Can you turn off the choke right away after starting a cold engine?

Check the float level, if its high you will get richness.

Clymer's manual has the jet numbers for the various model carbs used thru the years, send me the model number and I'll look up the jets. The late carbs were PD97AB, AC, & BA,

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PD97AC

Dropped the main jet from 110 to 102 today. No more fouled plugs and it doesn't flood out like it did on top. Still isn't quite right though. It also failed in the pilot department. Turned the needle all the way in and it doesn't die.

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Does the LTR200 have a smaller carb?

I have a TL125 and the carb is the same as the XR80 carb, so I pulled spare parts from an XR80 project I had going.

Besides the jets and needles, sometimes the slides are different. Something people tend to overlook.

When scrounging for parts, I use the parts fiche on ServiceHonda.com

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PD97AC

Dropped the main jet from 110 to 102 today. No more fouled plugs and it doesn't flood out like it did on top. Still isn't quite right though. It also failed in the pilot department. Turned the needle all the way in and it doesn't die.

Going that small on the main and turning the mixture screw all the way sure sound like the symptoms of a dirty air filter or high float level.

That is a 98-02 XR200 carb, 110 main, clip in center groove, 38 pilot.

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Doing the same thing now 2002 xr200r Head on Tlr200 engine Tlr cam would love to know best jetting for xr carb.

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I don't know what jetting to use with that combo because of the cam timing.  I do know that increasing displacement, compression, and cams on a XR200 usually requires a larger main but seldom any other great changes.  So my XR200 with bore, stroke, one point higher CR, high lift cam (near stock timing), and a freer breathing exhaust runs a stock carb with all jetting stock except for 3 sizes larger main.  

 

Basically all you did to the TLR is raise the compression one point and install larger ports and carb. With the stock TLR cam I would have considered starting out with a TLR carb as the XR carb is set up for a freer breathing air filter and exhaust system than the TLR units.

 

The other issue is the ignition system; I don't know the advance curve of the TLR ignition. But on my 218 build I used the XR200 ignition advancer.   I'm helping a friend build a XR218 engine on a TLR bottom end and we will use the XR ignition because we know the advance curve and how to adjust it for the higher CR. Initially it will go into a XR200R chassis for breakin and then to a BBR.

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Would like to use stock head and carb of Tlr only using xr head because angle of intake manifold stops me from using airbox.

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I don't know about a different port angle for the TLR head compared to the other two valve heads, but they do have smaller valves and ports. All of the 125/185/200/150/230 manifolds should bolt to the head but the port sizes are unique to the engines they were designed for, but a Dremel can fix most mismatches. The various manifolds do point the carb differently to suit their intended chassis/air box and are configured for the specific carbs.

 

I can only relate to the manifolds I have worked with; the twin shock manifolds pointed the carb towards the center of the bike, the monoshock manifolds pointed the car to the left. I found three different angles on monoshock manifolds; early XR200R, late XR200R, and CRF230F (which is a spigot mount for the carb).

 

Maybe a XR185/200 manifold would work (not XR200R).

 

Hope this helps.

Edited by Chuck.

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Would like to use stock head and carb of Tlr only using xr head because angle of intake manifold stops me from using airbox.

You could try this: ATC185S head, XR200 cam/ignition/wiring/CDI, XR185? manifold/carb, unknown intake boot, XR200 piston, 200X cylinder, slight frame mod to fit. Far stronger TLR still user friendly power. The TLR cam is likely to tame for the larger carbs-overcarbureted. Short duration cams can cause reversion problems that are just aggravated by big carbs. More info on classictrials website.

Edited by valvesrule

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The quick fix is to install the XR cam, then all of the top end parts will be compatible making it easier to sort out any carb issues. I've often thought that a XR200R top end was just what the anemic TLR needed. I have a TLR bottom end that I bought for a project and the TLR rotor is 21oz heavier than the XR200R rotor, that extra weight would really smooth out the XR bottom end.

Are you using the TLR or XR ignition systems? The XR uses a mechanical ignition advance with none in the CDI box, the TLR is all electronic with the ignition advance in the CDI box; mix and match won't work. The XR CDI box with the TLR sensor will provide zero ignition advance and could be causing your problem.

An ATC200X flywheel is very close to the same weight as the TLR and a good deal heavier than an XR. Very convenient if you don't want to swap to a TLR crank/flywheel. I've pondered the thought of using a toggle to switch from cam trigger to crank trigger for starting only but this combination starts so easy it might just be redundant.

Edited by valvesrule

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Honda did use a variety of flywheels on the two valve engines but they all seem to have different IDs making swapping difficult unless you also use the matching stator and the appropriate side cover.  Of all the rotors I have experience    with the only odd ball was the TLR 200 that had a larger taper than the others, and also a different left crank half. I put a 86+ electrical system on an early XR200R and the heavier flywheel really smoothed the idle.

 

TLR taper is 21.42mm,all others 19mm, TLR rotor bolt is 10mm OD, all others 8mm OD.

90-02 XR200R uses a 8x45 bolt, 86-88 XR200R use a 8x33 bolt, early XR200/R use a 8x40 bolt.

 

Some rotor info:

Year     Model           Flywheel PN               ID                 Weight

              ATC                                            85.28mm      3 lbs  4.3 oz

81-83    XR200R        31110-446-651       90.43mm      3 lbs  5.7 oz

79-80    XR185/200    31110-446-651                           

83 84     XL200R        31110-KG1-004                         

86-02    XR200R        31110-KT0-004      94.81mm      4 lbs  0.2 oz

81-84    XR200           31110-446-631                           

79-83    XL185S         31110-427-004                           

86          TLR200         31110- KJ2-671      90.43mm      5 lbs  3.2 oz

Edited by Chuck.

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Honda did use a variety of flywheels on the two valve engines but they all seem to have different IDs making swapping difficult unless you also use the matching stator and the appropriate side cover.  Of all the rotors I have experience    with the only odd ball was the TLR 200 that had a larger taper than the others, and also a different left crank half. I put a 86+ electrical system on an early XR200R and the heavier flywheel really smoothed the idle.

 

TLR taper is 21.42mm,all others 19mm, TLR rotor bolt is 10mm OD, all others 8mm OD.

90-02 XR200R uses a 8x45 bolt, 86-88 XR200R use a 8x33 bolt, early XR200/R use a 8x40 bolt.

 

Some rotor info:

Year     Model           Flywheel PN               ID                 Weight

              ATC                                            85.28mm      3 lbs  4.3 oz

81-83    XR200R        31110-446-651       90.43mm      3 lbs  5.7 oz

79-80    XR185/200    31110-446-651                           

83 84     XL200R        31110-KG1-004                         

86-02    XR200R        31110-KT0-004      94.81mm      4 lbs  0.2 oz

81-84    XR200           31110-446-631                           

79-83    XL185S         31110-427-004                           

86          TLR200         31110- KJ2-671      90.43mm      5 lbs  3.2 oz

The ATC200X flywheel is somewhere between the KTO and KJ2 weight wise.  It has a larger diameter hub than an XR so probably another half pound. It's an option to the TLR crank and flywheel for building a low cost and more common parts trials 200 engine.

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