Antifreeze

[1998RM250]

This weekend I finally got to ride the bike, and I noticed today that there was an oil film in the coolant that was not there before.
When I had no crank seals put it the shop said not to do the water pump seal because the shaft wears as well and it would leak. Theres a tiny bit of milk in the oil now, and I'm wishing I did put it in while the case was apart. (that is what you have to do right?) Also once the bike got hot after alot of riding, I heard that "pinging" metal on metal type noise when i was in the lower-mid rpm range coming on the throttle. I turned the mixture screw in 1/4 turn to richen it a hare. Also adjusted the powervalve to open a tad earlier and it felt like there was barely any tension on it, but it is working fine it seems? :whoa:

 

[whenfoxforks-ruled]

It has been a while since you first posted about this bike, it probably is due for a top end anyway? DID YOU FIND A NEW MECHANIC YET? Vintage Bob

 

[1998RM250]

It has been a while since you first posted about this bike, it probably is due for a top end anyway? DID YOU FIND A NEW MECHANIC YET? Vintage Bob

I've put about 15 hours on the Wiseco top end kit, I don't get to ride very often. I figure a few more rides and I'll pull it apart for inspection and re-ring. If I had the $$$ right now I would split the cases and install new crank bearings to be safe, the guy said it would be around $400 which isnt *that* bad right? There are no other mechanics around that I know of in this area, everyone goes to that one guy.

 

[helio lucas]

well, 400 for crank bearings seems to me kinda expensive but that´s maybe because we are spaced by atlantic...
in your bike i am not sure but on most bike it´s not necessary to split the cases, only pull the clutch cover (the big one if applicable) and you have to take the shaft out anyway to replace the seal.

 

[whenfoxforks-ruled]

If it needs seals and bearings already, thank you proclaimed mechanic. They should normally last a lot longer, with the exception of maintenance and the previous installation. If 1 seal is bad, replace all of them. Try and buy them in a complete set. closely check the main bearings, if it was me, I would replace them anyways. And use quality parts, really cheesy are available! With the exception of your mechanic, you do usually get what you pay for.

 

[1998RM250]

I wish someone that knew what they were listening to could ride the bike after its been ridden hard for awhile, it still makes this weird noise. Possibly pinging in the midrange throttle? I'd just hate to blow it up, itsa really clean bike. The bike was ridden in the 01' AMA pro races, then bought in 03' and hardly ridden until I picked it up last year. As for the water pump shaft, I guess they get "Worn" or a "groove" in them so the new seal wont seal properly? Got to love two strokes, I am literally the only one at the track.

 

[RM_guy]

You might still be hearing detonation and if so you'll need a higher octane gas.

The water pump shaft can be replaced at the same time as the seal. It's actually part of the impeller. Your mechanic sounds like a real tool. You don't have to split the cases but the right side cover has to come off. After that it's a pretty simple fix.

 

[1998RM250]

I know the previous owners were running sunoco race fuel, but they shut down that station. The motor was built by performance engineering http://www.peracing.com/co.html and has the head + carb modified. I've had the bike rejetted and its still making that pinging noise running a larger then stock main etc.

 

[RM_guy]

Try mixing 50% race gas.

 

[_JOE_]

I agree, it sounds like you have a detonation issue. You caould spend a bunch of extra money on race gas or have the head reworked for pump gas. Head work is cheap, so is the shipping. I'd pull it down to rering and send the head out.

I'd also suggest buying a decent tool set and a service manual. You can do most of the work that "mechanic" has been charging you money to mess up. If you have a camera you can take pics of anything you don't understand and someone here will be able to help you out.

 

[_JOE_]

And for that water pump, replace the shaft if it's grooved. Why not fix it right?

 

[1998RM250]

Thanks again guys for the advice

 

[whenfoxforks-ruled]

A new oem head does not cost but around 100 dollars. Get the bike back to stock form, it will run better, and longer.

 

[1998RM250]

where's a good place to get one from? I really appreciate everyone's help on here, I've learned ALOT.

 

[RM_guy]

Bike Bandit has them for $153 but you get 10% discount with an AMA membership and shipping is $8.95 http://www.bikebandit.com/2001-suzuki-rm250k1/o/m6589#sch256802

 

[2strokerfun]

If you can't get higher octane gas, you can sometimes work around mid-range detonation by changing jet needle. But this is sometimes a hit-and-miss approach and gets fairly expensive fast if you have to buy several needles to experiment with. I normally look up my needle in Sudco catalog and note the measurements and look at measurements of other available needles, make a edumacated guesstimate, drop about $50 on three needles and experiment. I usually get it close to right after about a few hours of trial and error. A much better way would be to note the needle number you have and call or email JD Jetting expert with the number and explanation of what's going on. People at Sudco are also pretty good at helping with this.
Or easier yet, going back to a stock head and jetting as Fox said.
I am the least anal-retentive person in the world, but I finally started to keep a log of all setttings on my carburetors: needle jet, jet needle, pilot, main and slide. Whenever I change something, I note it in the log, which is the back page of my three-year-old Sudco catalog. That darned catalog is invaluable to me when dealing with carb issues. One of these days, I'll order a new catalog. Probably the next time I drop some cash with the company.

 

[whenfoxforks-ruled]

Try Service Honda for parts? Unless its Chinese or a KTM!

 

[helio lucas]

it´s not the best approach but you can simply cut the head for running lower octane fuel. eric gorr still is a good source for the job.
as i posted previously, a thicker base gasket (or two of them) will do the trick.

run race gas to be real sure it´s detonation. one tank of race gas isn´t going to be the end of the world.

 

[1998RM250]

Great advice, I will try to get some race fuel when I'm out of town to make sure detonation is the problem. The guy who jetted my bike swapped my stock needle for this one he says "worked great" in his cr500's. I'm thinking this is an RM250 not a cr500, and I'm going to ask for the N3WK stock needle back. I might try lowering the clip a notch as well, but I dont want it to bog. Would the A/F screw help out at all fine tuning it? I turned it another 1/4 turn clockwise to richen it, maybe that will help a bit.

 

[jb_dallas]

If you are after head that doesnt cost $150, you might check out Ebay. Buy from a reputable seller. I have bought a ton of parts on Ebay and havent been screwed so far.