CRF 250 R will not start

Hi first post,
I have a 2006 crf250r which is not starting, I have had the bike in the shop and they could not get it to start and said it needed a full engine rebuild.

The symptoms, bike was getting hard to kick start on the last couple of rides when we first arrived at the forrest, however, it would roll start.
low compresion.
I took bike to shop and asked them to replace the valves or reshim them if that is all it needed.
Bike shop re-shimmed them as there is still life in them, but when they went to start, it would not kick over, even though bike has excellent compression now.
next step was the carby, they replaced the hot start float as this was seized and they had to drill out the old one, at the same time they cleaned out carb.
replaced spark plug.
put bike back together and still did not start.
called me and said the bike needs a rebuild, rings are worn.
Personally I don't think it needs a rebuild as it never missis a beat, never smoked, never rattled, always ran good.
I asked a few questions and found out that they only adjusted and shimd the intake valves and not the exhaust valves, I asked why and he said the exhaust valves never need doing?
the biggest thing he said was that a leak down test was performed and this is why they beleive rings and piston etc need doing, however, he told me the leakdown test was done at the start and it read 10% which was good, then after all the trouble and replacing items etc, they then did another leak down test and it read 50%,
the way I am looking at it, if it was 10% at the start then it should be 10% at the end and it should not change dramatically.

Any help would be most appreciated

Above post

Ol'89r said:

How many hours do you have on the engine?

Click to expand...

Hi, about 60 hours but personally I don't believe in rebuilds at this little amount of hours. I run most of my bikes around 150 hours before selling them with no engine work, a mate of mine just clocked 200 hours on his crf250 and it's still going strong

Ol'89r said:

The CRF engine is a modern, high revving engine and you can't put that many hours on them without doing some maintainance.

They run at a high RPM and have a very short piston. They only have two rings and if you let them go too long without changing the rings and or piston, you are taking a chance of destroying your engine. The piston skirt can break and the piston can turn sideways in the cylinder taking out a whole bunch of very expensive parts in the process. The valves need to be checked often. They can also break the heads off and cause extreme damage to the engine.

You can either spend some money now to do the proper maintainance or spend a lot more later to fix a blown engine.

Remind me never to buy a used motorcycle from you. ;)

Click to expand...

Cheers. I am still thinking that it is a different problem than the rings and piston. when he did the leak down test it was 10% then after doing the intake valves and carby it was 50%, something not quite rite, after looking over the bike I noticed a couple of washers missing from the subframe he pulled apart, makes me wonder what else could have been missed.

Ol'89r said:

If your bike won't kick start, you shouldn't bump start it. If it bump starts but won't kick start, that means something is wrong and if you continue to ride it, it will only get worse.

If I were you, I would find another shop. What they told you about the exhaust valves is untrue. Plus, if they checked the intake valves it would have only taken a few minutes more to check the exhaust clearance. The problem with the CRF valves is they tighten up instead of getting loose. When they tighten up, they leak. When they leak, the ti coating on the valve burns and they don't seal.

You either have burnt, (leaky) valves or worn rings. Pull the top end and check it out. What have you got to lose, it won't start anyway.

Click to expand...

yea thinking of taking it to another shop, I will have a play this weekend and see what I can work out.
Once I take the head off can I view the valves by eye and check them over without having the measuring guage?

Cheers guys

Okay, so I tried to kick my bike over again and it sounded like it was not getting fuel, I pulled the plug out and discovered the bike shop had put in a cheap plug for a 2004 not 2006, I checked plug and it seemed very dry, no fuel on it, I went to shop and bought correct $60 plug, tried to kick it over and still nothing, took plug out and still seemed dry, took valve cover off and noticed some light scratches on the underneath of the cover where it has the alloy plate, not sure if that is okay?
I put cover back on and tightened up without torque wrench, does this matter?
Next I rolled the bike on flat ground running next to it and jumped on and put it in 2nd gear and it fired straight away, let it run for 5 minutes and turned it off, tried to kick it again and it kept back firing which it has never done before, Also top end sounded very tappity, any ideas

IndyMX said:

It's not the plug...

Try listening to 89'r.. Your engine is shot. Time for a rebuild.

Click to expand...

Nah the plug is good. I am wondering if fuel is not getting to the plug while kicking it but then I guess fuel would have been there after I roll started it and then tried to kick it,
The inlet valves have just been adjusted and bike wOuldnt start, supposibly the exhaust valves were fine and did not get adjusted. See my original post first page

IndyMX said:

I did.. And you were told that your piston and ring were shot. I'd say that if you have low compression, which it would seem you do based on the fact that you can push start it but not kick start it, then you are losing that compression somewhere.

If a leakdown test confirmed that you are losing compression over time, like you said in your first post, and your valves have been recently adjusted, then you have to suspect the rings and piston are worn beyond limits.

There is only one way to know for sure. You must tear down and measure. And once you have it torn down that far, you might as well replace the piston, rings, wrist pin and anything else that is showing signs of wear.

If you continue to ignore the obvious, you are going to be riding around on a very expensive time bomb.

Once the piston goes and takes the valves with it, you will be spending quite a bit more than you can imagine to repair it.

Have you checked the prices on a new head and cases lately? I can tell you that a used set of CRF250 cases on ebay are about $250 per side. Throw in an extra 500 to 600 for a head, plus the cost for new valves and the labor to install the valves, plus a piston, rings and wrist pin, and you have yourself a ton of money you could have used to buy a lot of gas to break in the piston you need right now.

So... bottom line, quit trying to find a mystery problem that you can fix cheap and instead, pull that cylinder off and start measuring in.

Click to expand...

Thanks.
After the inlet valves were adjusted, I now have heaps of compression again.
Even tho the bike guy said it needed rings and piston, that does not mean much and I am sure he needs $2,000 as well.
I spoke with a Honda mechanic on Saturday and he is saying it sounds like valves.
Bike is back firing while trying to kick it which it never did prior to taking to mechanic.
Bike top end sounds loud and tappity which It never did prior to taking to mechanic.
Two leak down tests were done and both had completely different readings which is odd and something is not right.
Mechanic put in wrong spark plug, cheap plug.
When I took everything apart the bike had grit and grease on the screws which means they were laying on a dirty bench and personally if a mechanic can't keep his area where he works clean then how good of a mechanic is he, also missing washers on main frame as they took the carby off as well.