[Stefan]

Hey guys,

I was looking for some info about my newly bought Honda CRF 250R from 2008.
I have just gotten the a couple of weeks ago and rode about +/- 6 hours.
After this I wanted to do some maintenance.
Everything was fine and the bike ran great! A couple of friends have driven it to (experienced riders) and said it was fine.
But on my way home the bike stalled, after this i kicked it a couple of times and it fired right up so i didn't think to much of it.
When I got home i took the bike apart, and discovered the tank was empty . So I didn't see any problems.
After this i cleaned the bike, took everything apart and checked the valve clearance and sparkplug.
the valve clearance was spot (0,15 and 0,30 mm) on but the sparkplug was a bit dirty so i changed it (NGK R0409 B-8).
I also changed the engine and transmisson oil and engine oil filter.

but after this the trouble began, I can't get the bike to fire up again.
I checked everything there is to check about 6 times but don't see any problems
- cam/crank timing is correct
- spark is good, even tried the old sparkplug. (have to say it fits loosly in the ignition coil without the rubber sock)
- fuel is getting to the carburator and through the needle
- new airfilter is installed
- plenty compression


I have tried every kick procedure there is, bumpstarting the bike and what not, but nothing seems to work.
After about 8/10 kicks it sometimes backfires in the exhaust.
Has anyone seen this before?

I'm just recently getting into dirtbike so I haven't gotten al the knowhow but I am a diesel mechanic so I am somewhat inclined to wrenching. (sorry for the spelling, not a native Englisch speaker)

Stefan

[Aussiecrf230]

Hi Stefan and welcome to the site.

I am going to take a wild guess based on experience.
If you emptied the tank you may have ended up with a clogged filter or petcock.

Real bad when it gets to the carby and it needs a clean too.

Easy test pull the plug and pour a teaspoon of fuel in, put the plug in and see if it starts even for a little bit.

Assume there is fresh fuel in tank now.

[Stefan]

I got the problem fixed!

It took some time due to work but I got the chance to look at the bike again.
The problem was in the distibution chain tensioner.
When comparing the timing marks on the righthand and de camshaft everything looked fine, but when i looked through the left hand side again (ignition mark) it looked slighlty off.
So I took the tensioner out and reinstalled fully and then relieved the tension off the spring. After this the timing marks looked spot on.
Tried 2 kicks and the bike fired up immitiatly.
So my best guess is that I may have installed the tensioner with the spring out which may have put so much tension on the chain causing the crank and camshaft to rotate ever so slightly causing a no start.

[Aussiecrf230]

Stefan, glad to hear you got it sorted and thanks for the update.

[PLMX]

Hey I am not sure if you are aware but Mudline Motorsports offers a free tech support line. I was having issues with my 2015 CRF250R not starting last year and reached out to them, they walked me through what needed to be done and it was extremely helpful. Here is a link to their website!

https://mudlinemotorsports.com/