[Project250r.com]

Alright its been a few years since ive had a R that ran on race gas ... Lets refresh my memory.

I did a compression test 1st thing on this R that i recently bought. It has ESR310 cylinder, V force reeds, 39mm carb, ESR pipe..etcetc. Anyways, its roughly around 170 PSI compression. Do i need to run race gas? Previous owner said he was, but from what i remember, i thought 180 was the cut off point for pump gas. Maybe im wrong. Im not even sure what dome is in this head, he didnt know anything about the motor...it was bought then installed in the frame...and now i have it.
But ya, right now i have 5 gallons of C-12 to burn. Maybe it can be mixed 50/50 ?

Let me know guys

 

[2R's]

at only 170 ..it's either not a race gas head ..or the rings are going !!
mixing that c-12 w/93 pump gas should be fine (even tho the gasses never truely mix to be technical)...cause 190 is close or correct depending which(pump or race gas) true octane info you are using

 

[BLACKeR]

at 170 you shouldnt have a problem running premium pump.

 

[Project250r.com]

HE said it had a new piston in it when he got the motor..so hopefully its true. IT runs amazing. I dont know if i should tear it apart or not and inspect everything b4 i race it this springtime/summer...

 

[elbine69]

Probably would be a good idea to check it out now, instead of having to replace shit in the middle of race season.

 

[Teddy250R]

50/50 should not hurt, but with that compression you should be able to run 93-94. If you 50/50 mix it, I would go with VP 110, IMO, C12 is too much octane for compression and size of the motor.

 

[Saber]

Alright its been a few years since ive had a R that ran on race gas ... Lets refresh my memory.

I did a compression test 1st thing on this R that i recently bought. It has ESR310 cylinder, V force reeds, 39mm carb, ESR pipe..etcetc. Anyways, its roughly around 170 PSI compression. Do i need to run race gas? Previous owner said he was, but from what i remember, i thought 180 was the cut off point for pump gas. Maybe im wrong. Im not even sure what dome is in this head, he didnt know anything about the motor...it was bought then installed in the frame...and now i have it.
But ya, right now i have 5 gallons of C-12 to burn. Maybe it can be mixed 50/50 ?

Let me know guys

What compression gauge you using? Not all compression gauges read the same. I would get the number off the dome and call ESR. They can tell you what you should be running for fuel.

 

[RebelBanshee]

at 170 you will lose alittle power with 50/50 mix. Id check what dome it has, and check the rings. It could be the tester too, do you know it gives accurate readings on other bikes?

 

[Project250r.com]

I used one from sears..that i bought. Ill try the snap on tester soon and see if its the same reading.

 

[Michael88R]

If you look real close at the top of the dome, around where the spark plug screws in, there is a number. The last two letters should be something like PU or RA. Pump or Race. If it is not clear, give them a call and they can tell you.

 

[Teddy250R]

If you look real close at the top of the dome, around where the spark plug screws in, there is a number. The last two letters should be something like PU or RA. Pump or Race. If it is not clear, give them a call and they can tell you.

And the number also means something that is stamped on the edge of the head. I believe a lower number means a low-mid range dome, and the higher numbers are for top end. For instance a 77RA or 77-RA (can't remember) came with my 370 from ESR which is the biggest Pro-X top end dome they make.

 

[89_trx250r]

hey i also had a question about this. i just bought another r and it is an 87 and the owner has a full ct rebuilt with a bigger bore than stock just he doesnt know what size but he used to run c-12 and 91 octane in a 4to 1 ratio. which was 1 gallon c-12 and 4 gallons premium. would that help nad were can i get vp-110? is it cheaper than c-12 cuz with 5 gallons i can get about 25 gallons mixed up.

 

[Teddy250R]

You should be able to get 110 VP at any VP retailer. Generally it is about $5-$10 cheaper that C-12 per five gallons, at least in my dealings with my retailer. Go to www.vpracingfuels.com and do a dealer search.

I am not going to speak for everyone, but I would say generally that the extra money spent on C-12 is a waste, in my opinion. I would say that VP-110 is more than enough to satisfy 75-80% of the motors that currently run on C-12 (TRX) wise. I always ran C-12 in my 330 MX bike, and my 350 drag bike a few years back before I built my 370 when my retailer basically told me that I really don't need the extra octane for my application. He told me that you can get to a certain point where too much octane can actually hurt your engine's performance.

 

[mstohner]

You should be able to get 110 VP at any VP retailer. Generally it is about - cheaper that C-12 per five gallons, at least in my dealings with my retailer. Go to www.vpracingfuels.com and do a dealer search.

I am not going to speak for everyone, but I would say generally that the extra money spent on C-12 is a waste, in my opinion. I would say that VP-110 is more than enough to satisfy 75-80% of the motors that currently run on C-12 (TRX) wise. I always ran C-12 in my 330 MX bike, and my 350 drag bike a few years back before I built my 370 when my retailer basically told me that I really don't need the extra octane for my application. He told me that you can get to a certain point where too much octane can actually hurt your engine's performance.

what do you pay for 5 gallons of 110?

 

[89_trx250r]

yeah i found my local reatailer and he said that he sales the vp-110 for about 42 bux a five gallon jug. but my cuzin goes to fontana and pays 5.50 per gallon of the vp-110! so i think the little nifty gas container is not worth the extr moola. but im going to try and run it on 2 diffrent gases. the c-12 91 mix and the straight 91(with mix of course) and if isnt a bigger diffrence then im not spending my money on getting the c-12 or vp-110. but i changed the plug today and it was a chocolate brown!!! i was like that is nasty!!! and it has nice crisp throttle so i doubt its rich just i guess the plug is old. but thanks alot for the information. and when i do a compression test should i do it when cold or warmed up?

 

[Teddy250R]

what do you pay for 5 gallons of 110?

Right around $42-$45. I always get it in the 5-gal jug.

 

[Michael88R]

We've been buying a 54 gallon drum. It's about a dollar per gallon less than the 5 gal containers. Lasts about a year with 2 quads running 100% and one running 50/50.

 

[2R's]

hey i also had a question about this. i just bought another r and it is an 87 and the owner has a full ct rebuilt with a bigger bore than stock just he doesnt know what size but he used to run c-12 and 91 octane in a 4to 1 ratio. which was 1 gallon c-12 and 4 gallons premium. would that help nad were can i get vp-110? is it cheaper than c-12 cuz with 5 gallons i can get about 25 gallons mixed up.

the best thing to do is measure the compression ...& match the octane of fuel to it
IMO 32-1 is safest & performs fine on these size motors

 

[fastR of puppets]

We've been buying a 54 gallon drum. It's about a dollar per gallon less than the 5 gal containers. Lasts about a year with 2 quads running 100% and one running 50/50.

the problem with that is that it degrades in octane points, so by the end of the year it will probably be like running pump gas

 

[Teddy250R]

the problem with that is that it degrades in octane points, so by the end of the year it will probably be like running pump gas

I agree, thats why I never bought drums. Sure its great if you have 5 guys going in on it together and using it every week. But letting it sit and using it throughout the season is bad news by the time you get to the bottom of the barrel.