Motor Mods.....

[09RappySE]

In the next month or so I will get into the motor and was looking at the ESR kits, maybe the 310, I really don't want to split the cases.... what are your thoughts? are these kits worth it , is there a better way to go?

[rjs89ia]

im happy with mine. they're a simple bolt on and i haven't had any problems with communication at esr for support.

[09RappySE]

Did you go with the 310?

[rjs89ia]

yea 310 with trx9 porting. runs really well, i've probably only put 2 hours on it since my recent rebuild it'll get up and move. my first phase with this cylinder was with a used bottom end with a hotrods long rod crank assembly and pump gas dome, the powerband would hit smooth and wouldnt rip your arms off. i gathered up a ton of parts to rebuild everything this november and went with a hotrods short rod crank this time around and the race gas dome the powerband hits hard on this setup completely different beast from before. fuel cost about $6 a gallon for 100octane which i was told by esr you can run 93 with the new style race gas dome aslong as you dont run paddles or really tall aggressive tires. anytime you plan on putting a heavy load on the engine you should run 110 which runs about $10 a gallon depending on what brand you get.

[09RappySE]

Sounds great....race gas is not a problem as I already run it in both my raptor and LTR.

[RIDE-RED 250r]

Alot of people like to bash on ESR and in many cases they have had legitimate bad experiences to justify what they are saying.

Having said that, I had a very good experience with ESR. I have their 350 topend with race fuel dome, ATC5 pipe and silencer, their reedblock with TRX9 porting. This thing is quite a beast! It will be exactly 1 year tomorrow since I put it all together. I don't rack up huge miles on my R every summer, but I did manage to get about 8 gallons of fuel through it. First big riding trip I did have my cylinder base gasket blow out, but I think that was more my fault than anything. I replaced the gasket and put about 150 more miles on with no issues.

I am going to say that ESR can be a good option for someone like me who dooesn't have 2g to blow on trying out the CPI big bores. Mine runs well and I am very happy with it and ESR's service.

Oh, one final bit of advice.... Not wanting to split the cases is not a good reason to go with a 310 bolt-on. Even running the 310 you will be increasing the power by a fair margin and you should do a complete tear-down to be sure your bottom end and transmission are up to the task. At minimum, I would replace your crank bearings and seals and at the very least, send the crank to a shop and have it checked, (rod, lower rod bearing, etc). Also, you will want to at least have your CB bearings replaced unless you have done them recently. CB carrier replacement is a good idea too as the old cast OEM units get fatigued after 25 years and if they let go it's going to do bad things to your bottom end. I would recommend the ESR billet CB carrier. I have one and it is a quality piece, and very good insurance/peace of mind.

I know it sounds like I'm piling alot on, but these are some things you have to consider when you are looking at even an overhaul of a stock engine, let alone bolting on more HP... Gotta make sure the whole engine is up to the task....