1984 atc250r too much smoke

[RIDE-RED 250r]

Admittedly, I do not know off the top of my head what stock jetting is for the '83-'84 R's.

I do know the 81-82's run a smaller carb than the '85-'86's. Not 100% positive, but pretty sure the 83-84's do as well...

I'm having trouble loading the manual links posted, and of course at this point we don't know for sure what carb is on the trike in question..

But, it seems little odd that an engine running a bit smaller carb would be jetted that much fatter on the main than larger carb found on the water pumpers.

Not contesting the info you posted, just an observation.

You raise a good point about the clutch side crank seal too. Along with the excessive smoke, it's going to stink like crazy too. Not the kind of sweet smell of 2-stroke oil.

Would like to see some compression numbers on this..

[Islandbiker5000]

I thought maybe a crank seal it doesnt idle high tho. I can control idle very easily. My jets are the stock numbers. I got the information from freds honda. I cant tell if the oil is low because i just see a cap and no dipstick? Whats with that

[RIDE-RED 250r]

That is for transmission oil only. There should be a level plug somewhere on the clutch cover. Basically, just pull the level plug and if oil seeps out you are good to go. If not, ad oil through the fill hole till oil seeps out the level hole.

If you find that the engine is consuming transmission oil and not leaking it anywhere, that's a tell-tale sign of a bad clutch side crank seal as well.

[Islandbiker5000]

Yeah i see the threaded plug on the clutch side it doesnt have a stick. I rotated the crank and can see the clutch covered in oil but its not overflowing? I thought they only take a half quart of oil?

[RIDE-RED 250r]

You are correct, they take less than 1 qt. I don't know exactly what the models like yours take. I'm sure 300r can shed light on that.

Just check the oil level with the level plug on the side.

[Islandbiker5000]

If its a bad clutch side crank seal is that hard to fix? Or should i have someone do it at a shop? Ill have to pull the motor cuz no one works on trikes over here

[Islandbiker5000]

Ok i found the little plug. Its kinda rusty so im going to soak it with pb blaster and will check it in a few minutes

[yaegerb]

A couple tests I would do to make sure you are good to go. First, a compression test to see if the rings are still good. The correct compression is 156psi +/- 14psi.

The next test you need to perform is a two stroke pressure test. Below is a link to how to properly perform a pressure test and you can also purchase the three way valve from Harry Klemm himself. Harry is building mine right now and its a helluva lot cheaper than the motion pro tester. The motion pro tester is below the klemmvintage link.

http://klemmvintage.com/airleaks.htm

http://www.ebay.com/itm/Motion-Pro-2...4a0208&vxp=mtr

[barnett468]

Hello


Hope no one misunderstands this post. I have no intention of ruffling any feathers or contradicting anyone regarding their claims of what the stock jetting of an 81 thru 84 ATC 250R should be. Since this post can be read by anyone who pulls it up in the search engine I personally think this info is important so they do have the correct jet setting to start with as a baseline for their bike. I am also curious myself to find out the reason for the discrepancy in the info. It is possibly that the info supplied in the OEM Honda manual is an error but it would need to be disproved through documentation if possible to render it so.

The previous info I posted is direct from Honda not me. It comes from a 1983 version. If anyone cares to dispute the accuracy of Honda’s information please call them directly at 310-783-2000 it has nothing to do with me. If anyone has PROOF that there is a jet setting in another official OEM Honda service manual, OEM Honda service bulletin or OEM Honda parts manual please post it and the print date/year of that manual etc.

There are other online and paper sources [Clymer manuals etc]that supply jet info however that info is subject to accuracy and/or interpretation including the info Islander received from “Fred’s” Honda shop. They did not give you this info directly from the OEM manual I POSTED. The likely hood of them having an OEM Honda Parts manual is virtually non existent therefore the accuracy of their info is questionable.

If one had purchased a NEW bike in 84 that the dealer had not already rejetted because it ran to bad to sell or purchased an NOS Caburetor in a FACTORY SEALED BOX then this info however well intentioned is also questionable.

After working at Kawi R and D and being a parts manager at a large Honda Kawi store I have seen a lot of unusual things. Based upon this I personally believe the Honda manual only no matter how strange the jetting might seem to be.

xxxxx

Stock jetting on the 83-84 250r.is 130 on the main 50 on pilot. I have two stock 83-84 250r carbs.They are 30 mill Keihins.both have stock jetting 50 130.

Please see intro comments.

xxxxx

But, it seems little odd that an engine running a bit smaller carb would be jetted that much fatter on the main than larger carb found on the water pumpers.

Yes I understand and agree on the surface it certainly does seem strange but t this can be due to many mechanical variables. Please see intro comments.

xxxxx

I have two stock 83-84 250r carbs.They are 30 mill Keihins.both have stock jetting 50 130.

Please see intro comments.

xxxxx

My stock 85 250r carb is round slide Keihin 34 mill.with 140 main jet.

The official Honda manual I posted for 85/86 says 142 is stock, the 140 is or elevations between 33000-6600 ft and temps between 22 and 104 deg F. or 5000 ft and above and temps between 0 and 22 deg F. This jet setting is done at the discretion of the customer NOT by Honda.

FROM PG 3-2 OEM 84/85 ATC 250R MANUAL

85 CARB # PE37A 142 MAIN 142, PILOT 52, 86 CARB #PJOSA MAIN 145, PILOT 42.

xxxxx

My manuel also says the jets I listed are stock .

Please post photo or give exact mfg of manual and if it is an OEM HONDA manual please supply the print date/year on bottom of front page.

xxxxx

I thought maybe a crank seal it doesnt idle high tho. I can control idle very easily.

It will almost always have a high and/or erratic idle if this is the problem but check it anyway.

Xxxxx

My jets are the stock numbers. I got the information from freds honda.

Not necessarily, please see intro comments.

xxxxx

If its a bad clutch side crank seal is that hard to fix? Or should i have someone do it at a shop? Ill have to pull the motor cuz no one works on trikes over here

If you have the tools you can probably do it yourself after watching video if you are mechanically inclined.

Are you saying they will work on the motor but will not allow a 3 wheeler into their shop?

xxxxx

One way to check the flywheel side seal is to pull the flywheel cover off and see if it smells like gas.

It will almost always have a high and/or erratic idle if this is the problem but check it anyway.

xxxxx

Below is a link to how to properly perform a pressure test and you can also purchase the three way valve from Harry Klemm himself. Harry is building mine right now and its a helluva lot cheaper than the motion pro tester. The motion pro tester is below the klemmvintage link.

You can also use a cheap radiator pressure tester


Xxxxx



Hope this and others info helps.

[barnett468]

Hello Islander


I personally would not ride or re-jet the bike until you do your compression test and crank vacuum test as recommended and determine the cause of your excessive smoke. In my opinion there is no point to it. Doing so could damage it further. I know it's a pain.

[barnett468]

Hello

Even if the OEM manual is incorrect installing a main jet that is larger than the OEM setting will do no harm providing it is temporary. It will simply load up the plug and run badly if it is too rich, however installing a main jet that is substantially smaller than the OEM setting can quite possibly do damage to your motor if it is left in for even a brief time. I personally think it is better to be safe than sorry and would simply start rich and go leaner as necessary instead of the opposite when there is any questions as to what an OEM jet setting is but that's just my opinion.

[barnett468]

Hello Islander


I forgot to mention Honda says that 158 main jet is for all 81 thru 84 atc 250r's and the carb number for all those models is PE23A. Look on the side of your carb and post all the numbers and letters you see any where on it.


On the inside of the forst oge of the m81-84 manual i mentioned above it says "issiue date August 81'", on all the other pages it says "issue date May 81'". This means this is a factory re-issue of the the original 1981 manual with no revisions, so in 81 they apparantly planned no jetting changes all the way thru 84 and because there are no revisions this is exactly what they claim they did. Interesting. So anyway like I mentioneed, if anyone has a factory manual different than this one with a different jet setting please post the info.


Thanks

[bkm]

A couple tests I would do to make sure you are good to go. First, a compression test to see if the rings are still good. The correct compression is 156psi +/- 14psi.

The next test you need to perform is a two stroke pressure test. Below is a link to how to properly perform a pressure test and you can also purchase the three way valve from Harry Klemm himself. Harry is building mine right now and its a helluva lot cheaper than the motion pro tester. The motion pro tester is below the klemmvintage link.

http://klemmvintage.com/airleaks.htm

http://www.ebay.com/itm/Motion-Pro-2...4a0208&vxp=mtr

Yeager is spot on. On an older machine, any machine, the internal condition of the engine must be evaluated before any tuning can be performed. You're pretty much pissing in the wind until you have verified the condition of the engine. Then you need to evaluate the carb condition. A worn out carb, even if clean, is still a worn out carb.

This is just my .02, but if funds allow it, ditch the stock carb and buy a newer, better replacement. You will thank yourself in the long run.

[Islandbiker5000]

Hi all. All your info has been simply badass and i really apreciate it you have no idea. I just did a compression test and the result was 132 psi. Should i replace the rings? And or piston?

[yaegerb]

Hi all. All your info has been simply badass and i really apreciate it you have no idea. I just did a compression test and the result was 132 psi. Should i replace the rings? And or piston?

Yes, I would replace the rings and step up one size on the piston and bore the cylinder, unless you find that all you need is a hone job. A reputable machine shop will be able to tell you if you need a bore vs. a hone....or take pictures and post them up here for us to look at and evaluate.

Also, before you go ripping into the top end, I still recommend a pressure test so you can see if any of your seals or gaskets need replacing. Its highly recommended to do this prior to any other work, that way you can build it 1 time instead of taking it all apart and THEN doing the pressure test, only to find that you have to do it again.