CR250 needing to run race fuel?

**honda_power** · 13th January 2009, 15:28

Im looking to buy a low hours good condition CR250 from a mate of a mate.

Iv read up on the net, and the 05-7's seem to have trouble with 'pinging' [whatever the hell that is] and jetting.

Seems the only fix is to run race fuel or 'retard the ignition' [what does that involve?].

I havnt acually talked to him about what fuel it runs etc yet, but how common is this problem, and is it an easy fix? I dont wanna have to run race fuel or jet it all the time [i dont even know how]. The whole point of going to 2 stroke is for a break on the maintanace side... seems these are more trouble than the bloody 4 strokes. Is 96-98 fuel enough?

I know some of you said to stear clear of the CRs, but iv ridden hondas for the last 5 years or so, plus this CR is a bargan, and its kind of hard to ignore in search of a good YZ.

Chur

**B0000M** · 13th January 2009, 15:37

if you run 91 you will eat pistons and cylinders. if you run 95 you will hear the odd ping, if you run 98 they are sweet as.

as for jetting, im running a fatty pipe, shorty muffler, boyesen reeds, jetting is standard apart from the main being a 430 and it runs good as, never fouled a plug, no excess smoke, no oil spooge in the muffler - couldnt be happier with it

**honda_power** · 13th January 2009, 15:51

Originally Posted by B0000M

if you run 91 you will eat pistons and cylinders. if you run 95 you will hear the odd ping, if you run 98 they are sweet as.

as for jetting, im running a fatty pipe, shorty muffler, boyesen reeds, jetting is standard apart from the main being a 430 and it runs good as, never fouled a plug, no excess smoke, no oil spooge in the muffler - couldnt be happier with it

thanks mate. i am a bit worried about the cylinder though. Suppose something does go wrong... what would the total damage bill be? Its just that im gonna be a student once again for a year and im not too keen on having huge un-expected bills popping up.

**B0000M** · 13th January 2009, 16:24

you'll hear it long before you fuck it.

basiclly if it sounds like the motor is rattling like fuck under hard acceleration, your doing damage. put it this way, my bikes done nearly 170 hours, cylinder still looks like new with the hone marks, ive only seen one eat itself and it was being raced, and was running 91 fuel - actually it was an 04 as well

**honda_power** · 13th January 2009, 16:32

Originally Posted by B0000M

you'll hear it long before you fuck it.

basiclly if it sounds like the motor is rattling like fuck under hard acceleration, your doing damage. put it this way, my bikes done nearly 170 hours, cylinder still looks like new with the hone marks, ive only seen one eat itself and it was being raced, and was running 91 fuel - actually it was an 04 as well

ok sweet thats what i wanted to hear

. I best go have a look at this thing then. Anything I should look out for? its an 06

**jt119** · 13th January 2009, 18:27

ive got ann 04 and it seems alot better on 98 than 91

**B0000M** · 13th January 2009, 19:04

nothing in particular i can think of to look for, just make sure everythign works as it should, check play in the suspension bushes, chain, sprockets, compression compared to others, how it goes when you ride it, straight brake discs, pad condition, suspensions smooth action / not noisy, condition of radiators.. just the usual stuff.

if it doesnt have one allready, get youself a fmf fatty and shorty, they make the bike.

**Brian d marge** · 13th January 2009, 19:34

By crickey ,,that 91 of yours must be dodgy I run my crs on Japanese 91 ...tis what they are designed for ,, with no props what so ever , no sign of detonation

what they watering that stuff down with ,,,,

Stephen

**scott411** · 13th January 2009, 20:16

yes our pump fuel is very average, and rated different to most of the world, ,
race fue/av gasl blended 50/50 with 91 is what i reccomend for serious racing on 2 strokes, you can normally jet out the denotation for trail riding and light mx use,

**warewolf** · 14th January 2009, 13:03

Originally Posted by scott411

yes our pump fuel is very average, and rated different to most of the world

For the curious amongst us, please explain?

AFAIK fuel here is rated as RON like UK/Europe, as distinct from the US system of (MON+RON)/2 which results in a lower number for the same stuff.