Servicing a lightly used '02 XR650R

I finally found a nice '02 XR650R that appears to have had very little use. It looks like new, starts easily, and sounds tight.

Once it's warm, it idles and runs good in low and midrange RPMs but sounds like it's staving for gas at WOT and cuts outs/chops as I increase throttle.

It's been sitting for months with Stabil and the gas did smell and look old so I dumped it and filled with fresh. I checked all fasteners after reading the "Pig Pen" lookout points (kick starter bolt WAS loose) then took it for 20 minute ride to run the old gas out of the carb and get the engine to running temperature. It ran a little better but was still cutting out when I give it more throttle.

Am I correct to assume that the main jet is partially pluged from gum/varnish?

Is there anything I can use to "chemically" clean out the carb? I've heard of Sea Foam but does something like this work?

I do plan on uncorking it so I'll have new jets and needle once they come in but was just wondering if there is anything I can do, that is work while, while I wait on parts?

Thanks for any help.

1.) Am I correct to assume that the main jet is partially pluged from gum/varnish?

2.)Is there anything I can use to "chemically" clean out the carb? I've heard of Sea Foam but does something like this work?

1.) It's a definite possibility.

2.) Many people swear by fuel additives and cleaners. I, however, am of the mind that there is usually no easy fix. With how simple it is to pull the carburetor and clean it, there isn't really any point in trying to cut corners here.

I will be pulling it apart as soon as I get the parts to uncork it but was hoping there might be something that works as a chemical cleaner while I wait. I've read on here that Sea Foam is good but never tried it.

I would like to make it run well before I uncork it but I might as well pull the carb and just clean it. I'll be doing it several times once I start uncorking it to get it jetted correctly so I might as well just do it now and get familiar with the carb internals.

Thanks for the reply.

Brake cleaners usually break up varnish reasonably well as do official carb cleaners like Gumout. You don't have to pull the carb to change the jets. Just drop the float bowl with a rag/towel under it and the jets will be right there looking at you.

I disassembled the carb tonight and sure enough, it was pretty nasty in the float bowl where gas had been sitting. How long does it take gas to corrode jets like that?

The rest of the carb looks pretty clean.

Should I just soak and clean the jets and other parts in the bowl or should I disassemble carb completely and soak it and should I look for anything in particular?

Hopefully, this is the cause of the poor acceleration problem.

gum1.jpg

gum2.jpg

gum3.jpg

It really depends on the area, temperature, atmospheric conditions, and gasoline formulation. Depending on storage, that much varnish could form from sitting for just one season or a couple years.

I don't see any evidence of moisture corrosion, so that's good.

Soak it /spray induction claener on the parts. My carb was bad but nothing like that I used induction cleaner & it cleaned up like new

Since no body else has mentioned it, Honda was very stingy with the grease in the steering head, swing arm & rear suspension links. Do yourself a favor & re grease/inspect these now.

I took the old gas to a fire pit and poured it on some wood I was going to burn. I lit a rag and threw it at the gas like I've done a hundred times before but there was no vapor to burn. The rag landed on the gas and it burned but not very well. It was old. The funny thing is that the bike started and idled good on that old stuff. I was surprised

I'm heading to the parts store to get some cleaner and will start cleaning it up later tonight.

LT1Coupe, I have already regreased the swing arm and rear linkage bearing. Pulled the wheels and greased the axles as well. I'm going to grease the head bearings this weekend. Thanks for the tip.

Once it's warm, it idles and runs good in low and midrange RPMs but sounds like it's staving for gas at WOT and cuts outs/chops as I increase throttle.

wsettle:

That's exactly what my XR600R was doing after I bought it.

I ignored the problem until she would sputter and gag at ~40mph.

It turned out the tank and carb were gunked up with black slime from the gas cap gasket, not to mention varnish from old gas. I was amazed the bike even ran at all, after seeing the junk in its fuel system.

Anyhow, I tossed the old tank and fuel line, added an inline fuel filter and had a pro go through the carb (I've learned enough to do that part myself in the future). Now she runs better than new!

I share this story as another reminder that your problem is probably very minor. :thumbsup:

it might be running poor on the top end because it cant get enough air carb is nasty and needs cleaned but i dont think it has cloged the main jet might just be a need to uncork it.xx

Thanks for the replies everyone. I got the parts to uncork it yesterday. There were 5 parts as described on 4-strokes, http://www.4strokes.com/tech/honda/650rmods.asp

With some CRC brake cleaner, a brass tooth brush, a nylon tooth brush and some Q-tips I cleaned as much of the varnish off as I could and it turned out looking almost new.

I know, I left the jet holder off for the picture but it cleaned up pretty well and I installed it when I realized I had a part left over... DOH!

I also filled the gas tank with fresh fuel and a bottle of gumout and let it sit overnight. I drained it this morning, removed the petcock and cleaned it really good and put everything back together then put some more fresh fuel in her.

I love this bike, it is so simple to work on! Anyway, I took it out for a test ride to see if it fixed my problem and it's like a new bike. I cannot believe how hard it pulls. It's freakin amazing! WOW! I really want to yell a couple of choice cuss words to share my enthusiasm but will restrain myself. So I'll just have to say Wow! again! WOW!

Bottom line, problem solved and I got to take my first real ride on this bike. After going though the carb, greasing it and really looking it over, I believe the bike has not see many hours of use over it's life like the PO told me. There is virtually no wear on anything. It's almost too good to be true to find a 6 year old bike in such good shape.

Thanks everyone for the support and here are a few shots of the cleaned up carb and my new pig. I'm finally a member of the discontinued club :thumbsup:

cleanCarb-1.jpg

cleanCarb-2.jpg

bike-1.jpg

bike-2.jpg

Wow, you have a really nice example of a low hour bike. I am so jealous.

Now go enjoy your new toy!

I rode it some more this afternoon and this thing rocks! It pulls so hard. I love it.

I jetted it according to the pig pen's jetting guide, http://www.xr650r.us/jetting/ for my altitude (~750 ft.) and temp this time of year and selected a 175 main.

There is some decelleration popping when I roll off the throttle. Can someone explain why it does this and can/should I do anything about it?

Thanks for any insight.

Excellent!

Now you can get to work on the farkles.

Try plugging the AJCV as described on the link.

http://borynack.com/XR650R/xr650r_caruretor.htm

Nice looking bike too. Congrats on the find!

Thanks for the link. The AJVC fix looks promising and I'm looking around for rubber plug like Borynack used but have not found anything yet. It will make it reversable which would be nice so I'll keep looking. Will head to the hardware store tomorrow.

That page had another interesting tip about the choke plate so I did some more searching on TT. I see that XR600s seem to be prone to the choke plate breaking apart but does the 650R have the same issue? It appears that he is just making sure the screws don't come loose but I haven't found any supporting threads that support the issue and he didn't go into great detail about why it's important. If the screws are crimped on the end, what's the issue?

Thanks for the link. The AJVC fix looks promising and I'm looking around for rubber plug like Borynack used but have not found anything yet. It will make it reversable which would be nice so I'll keep looking. Will head to the hardware store tomorrow.

Not wanting to make it difficult to reverse myself, I used a piece of an o-ring. The o-ring that fits the oil filter cover on my wifes TRX400 quad worked perfect. I did have to heat the tip a bit and round the edge to a small taper to get it started in the hole but fits real snug. I believe its the same o-ring on the 650L.

I used a piece of an o-ring.

Brilliant! Thanks.

hi wsettle, did you change the plug as well?

I also just but an '02 but it's by far not as nice as yours. A bit of a project bike, actually.

I took it in for a compression test and it checked out just fine. The mechanic called me as he couldn't get it started (hehe) so I went by and fired it up for him (one kick). I blows a bit of black smoke. It's been jetted and has a White Bros. pipe on it. Then mech said he changed the plug as it was fouled but that it was likely that the carb was all gummed up. He said I should clean it out but not to leave it sitting in carb cleaner longer that 1 hour as it could corrode some parts (?)

Anyhow, just wondering if you should maybe change the plug as well.

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