August 2010 11

Hello, I love this blog and the forum is a great idea, good work. I’ve got a 1995 KTM 620 that I’ve been trying to find a repair manual for, so I can adjust the valves and maybe do some top-end repair work some day. The manual isn’t available anywhere! I’ve tried hours of searching the internets, ebay, local dealers, forums, etc. I realize this bike is ancient by dual-sport standards and is now becoming “obscure”, but I’ve seen some other KTM-related posts on here so I thought I’d ask. Also: what do you think about using synthetic oil for this bike? I’m familiar with the arguments about friction modifiers and so forth, but I’m also noticing a lot more seepage coming out of the motor now that I’ve tried using synthetic on this old Katoom. Were those gaskets too old for synthetic oil’s super slipperiness? Thanks!

Hey Cap` thanks for the positive comments!

I don’t have a manual handy for the early LC4 motors, but there is plenty of information floating around out there. If you are just looking for valve clearance specs and cylinder measurements I’m sure I could dig them up. Are you riding a Duke model? Or one of the SX models?

As for oil – If the bike hasn’t used synthetics from the start I would avoid them. The seeping you noted is extremely common when switching and older bike to synthetic oils. Synthetics are able to make their way through microscopic holes in the gaskets that dino oils can’t. If I was you I would just switch back to dino oil and call it done. Keeping the oil and oil filter clean are far more important than selecting between dino and synthetic. Use dino, change it frequently, ride happy!

Cheers

I just bought the bike. Former owner told me the bike runs rough when the outside air temp is below 65 degrees. I should say the bike runs rough till it gets warmed up , but it takes a long time to warm up. I live in Michigan the ridding season is short and temps are cool for a large part of the season. Is there anything I can do to change this…different spark plugs or do I need to be patient and let it warm up for 10-15 min when it is cool out.

Do you know where I can find an owners manual and repair book for this bike.
Thanks
Your web site is Great

Lots of air cooled bikes tend to be cold blooded. In my experience the Honda CM motors aren’t particularly prone to this. I would guess that your bike just needs a nice little tune up. When was the last time the valves were adjusted and the carburetors synched? Both of those can cause hunting idle and sputtering, particularly when cold.

I believe I have a manual for this bike. Let me check and I’ll repost with it shortl

Note from Reader:

Evan,

I just bought an ’82 Honda CB450 Nighthawk. The owner told me all sorts of lies about the bike. Needless to say she is a basket case. Good thing is I was able to get her started (one cylinder only) but she did idel well and sound ok (no wierd knocks or anything). I am also looking for information on this bike. I would rather get my info for free while working on this bike. I do have a copy of the repair manual for a Honda VTX 1300 ’05 on email if you could use it also one on 2009 Kawasaki Ninja 650r. Also looking for parts on this bike. The bike fixed up is not worth much but every time I see parts for sale they are asking more for the parts than the bike is worth. Makes no damn since to me. Need info on rebuilding carbs most of all. Thanks for your help.

Unless your carbs are truly trashed then there is no reason to buy replacement parts for them. Start out with what you have and give them a good cleaning and reconditioning.

You can just follow my carb cleaning article here: How to Clean a Motorcycle Carburetor

What parts specifically are you in need of? Tanks, seats, and plastics will always be expensive for any old bike.

Also – Sure, I’d happily accept those manuals from you and put them up on my site for download.

Cheers!

Is the thing on the left of my motor the secondary air injection system?  If so can I remove it?

You likely are referring to the smog and emissions control units which are now part of all the XR650L bikes when new from the factory. They are commonly removed and their ports blocked off. There are some great articles about this on the net. You’ll also end up re-jetting slightly to compromise.

This is the very first thing that should be done if you are attempting to ‘uncork’ your bike.

Have a gas tank I fixed and painted. I used the krylon paints to finish the project and it looked great. Then I put gas in and a drop fell on the pain that was a week old. It made the paint soft and almost like a bubble that was deflated. I thought it hadnt cured but recently had a seal leak and some fuel ran onto the tank. Now the whole side is soft and stickey. What type of paint should I have used? I cant seem to find anyone with an answer locally so thought I would come to the master of restoration.

Note from Reader:

For rattle can – Engine Enamel is very fuel resistant. The kind that is lower temperature (usually rated to 500F) comes in all sorts of colors.

Note from Reader:

I think Eastwod has a clear paint in a can that is chem resistant. If you use it as a top coat you can paint anything you want under it. They also have lots of powder coat colors, no problems with gas there.

My Comments:

I think Eastwod has a clear paint in a can that is chem resistant. If you use it as a top coat you can paint anything you want under it. They also have lots of powder coat colors, no problems with gas there.

I have an 09 XR650L. Will the uncorking procedure used on the XR650R work on my XR650L?

Hi Ghost –

The XR650L is also a bit anemic from the factory, particularly if you are in California where they come with the emission control cannisters and whatnot.

The procedure is not exactly the same, but the principles are. The goal of ‘uncorking’ any bike is to reduce airflow restrictions so the motor can breath better. On the XR650L you can remove the rubber baffle on the top of the airbox, replace the air filter with an aftermarket unit, you can drill out the slide a little bit too (for the XR650L carb mods do a search for Dave Closs, he has all the details written out). I know on the earlier models the exhaust mounts where the pipes meet the motor have welds that can be ground down with a grinder. This was common on XR600’s, 650L’s, and XR400’s, but I’m not sure off hand if it has been fixed over the years. You can pull of your headers and take a look to see if there are welds bulging out a little on the inside.

I think you’re better off replacing the stock muffler rather than modifying it.

Hi evan,

So I just bought a maxim 550 and have noticed that when it’s idling, cold and warm, it’s starts out fine then slowly dies off untill it stalls. It will run fine when the throttle is reved and when the choke is on.

I’m just wondering what the cause is and what I can do to get it to a smooth idile.

Cheers,
Pat

Hey Pat – Have you adjusted your idle setting at the carb? There is a big knob at the between the middle carbs. With the bike warmed up and running turn up the throttle 1/4 turn clockwise at a time until you find a good setting.

If you have already done this let me know.

Well I just took it out for the first time yesterday and the idiling problem seemed to stop after driving it down the hy-way and really warming up the engine. I will be doing a tune up this weekend and pulling the carbs off so I will make sure to readjust the throttle setting.

I was also wondering if you had an electronic service manual for this bile. It’s a 1981 maxim 550.

Thanks for your help and this web site it’s great.

Cheers,
Pat

On any carbureted bike the bikes performance as well as idle is going to vary from day to day based on air temperature, air density, humidity, gasoline quality, and running conditions (cross country, in city, etc). The variation will be slight. On any bike I ride I regularly adjust my idle to keep it purring at the proper rpms. If it wants to stall turn it up a little, if it’s running fast, turn it down a bit. If it’s jumping around then that can be a different issue.

On my single cylinder bikes (which in my experience are more susceptible to variance), I’ll adjust the idle every time I ride, and often several times throughout the day as the riding conditions change.

I’ll see what I can find for a manual. I have at least one of the XJ cruiser manuals here somewhere. I know I have the Seca manuals.

My son has a ’82 KZ750. He has put a lot of work into painting and some customizing. He just found out he will need a ring job. Compressions are in the 80-90 and one is 10. I also suspect he will need a valve job too. I have been looking but I am having trouble finding parts. Does anybody know where I can get the parts to do a overhaul?

We are debating to do the work ourselves or take it to a shop. I have a lot of experience with auto’s but very limited for bikes.

Any help is appreciated.

If you’re experienced with auto motors then you’ll have no problems with the KZ.

For parts you’re going to want to check Partsnmore, Cycle-recycle, oldbikebarn, and maybe even some of the bigger boys like bikebandit. You’ll also be surprised what you can turn up for NOS parts on ebay.

If you’re looking to do it on a tight budget it might end up being cheaper to just buy a used top end from a salvage yard.

just wondering if there is any other carb that will work on this bike,Pete

Hi Pete-

Sure – there are lots of carbs that could be made to work, how much time and money do you have?

If you are looking for a 3 carb bank that’s a direct replacement, you won’t find any. The stock carbs are your ticket. Clean and synch them and be on your way. If they are trashed, just get a replacement rack off of ebay or a local salvage yard.

I recently bought a 1978 suzuki fa50 on craigslist. it is missing the key slot, it starts w/out it. it is also missing the back rack along with backlight and blinkers. How expensive do you think these parts would be and to get a motercycle shop to install it for me?

There is NO sense having a shop install parts for you on any old model bike. Buy the used or new replacement parts and do the swap yourself. A shop will charge you big money to work on any older bike.

You only need a modicum of tools to perform the vast majority of jobs on most bikes.

hi there,

as the subject suggests, i bought a 73 cb500 late last year and didn’t have much opportunity to take it out, but it seemed to be in good running order. i took it out towards the beginning of the warm season this year for a fairly substantial ride (about 70 miles or so), and about half way into it the bike started sputtering and lost all acceleration. at the time i was on the interstate so i had to pull off to the side of the road. luckily, a motorcycle enthusiast with a trailer happened to be passing by and saw me and offered a ride to the nearest gas station. his thought it looked like my ignition coils were going bad and needed replacing. after about 15 minutes i started the bike back up and made it the rest of the way on my trip fine. i have since ordered some new coils, but in the mean time have tried taking the bike out for short rides (a few blocks short). unfortunately the problem seems to be getting worse. additionally, i now notice that it wont even start without the choke engaged, and if i attempt to turn it off while running the bike dies out. any thoughts?

– kyle

Hey Kyle –

If the choke is a variable in the equation then the carbs are always the issue. I would imagine your coils are fine, it’s pretty rare that coils fail.

The heat and vibrations from riding can stir up debris in the carbs or in the tank and it can find its way into places where it shouldn’t be. You should definitely pull your carbs and give them a good cleaning. You might also drop your petcock and see if there is a lot of gunk in the tank that can be flushed out.

Let me know how it goes.