Hi guys,
New to the site. Happy to be here. I am building an Exciter oval racer and need a little help. I plan on running twin carbs and pipes. The carbs issue has been solved and now I'm looking for some help with the exhaust port timing.
The pipes i'm looking at are originally for a GPX433. I would like to know what the measurement is from the top of the cylinder is to the top of the exhaust port. I thought it was something around 26 1/2 mm. I would like to port it to GPX specs to get the most out of the pipes.
Thanks guys.
New to the site. Happy to be here. I am building an Exciter oval racer and need a little help. I plan on running twin carbs and pipes. The carbs issue has been solved and now I'm looking for some help with the exhaust port timing.
The pipes i'm looking at are originally for a GPX433. I would like to know what the measurement is from the top of the cylinder is to the top of the exhaust port. I thought it was something around 26 1/2 mm. I would like to port it to GPX specs to get the most out of the pipes.
Thanks guys.
Gorkon
New member
I think, if the race rules allow, you would be better off buying pipes from Aaen, Delaughter or someplace like that. Modern pipe builders pull more power out these engines than we ever thought possibly back in the day. G.
Yamaha Nutz
New member
stock height on the gpx's very but most and 27-28 mm depending on the rules for the organization the twin carbs are illegal in most places a exciter will never come close to making the hp that a gpx makes although alot can be had with just a little work and a 40mm carb and good clutching i have set up 2 ex 440's that where race at a lake cross that pulled away from a polaris centuian and anthing goes at this race but these sleds where mostly stock (i can do alot more to the motors) if you are dead set on this the best pipes to use would be the 74 gpx pipes ............................ even though the motors are close in design there are many factors that limit the exciter plus if you run mod no matter what you do you will be at the bottom of the hp scale ....................unless you think you can pull upwards of 110 hp out of that exciter and i know that is not possiable
rvdave@live.com
New member
suspension?
what type of suspension are you going to use?
what type of suspension are you going to use?
I have a set of Northstar skis on ski spreaders, tightened the limiter strap up on the rear suspension and going to try it out that way first. I have a Polaris primary with blue spring and 26's in it now.
I cleaned up the transfers and raised the exhaust ports from 30mm to 28mm. The crank has been trued and balanced. I'm going to run a set of pipes from Koch Performance and I'm thinking of having someone reshape and modify the heads over the summer. I have the rack carbs off of a v-max 600 (38mm) and Cr-125 vforce 3 reeds. I just have to find a way to mount the carbs. I can't find a carb boot to work unless I make an adapter.
I'm looking to make around 60 to 70 hp. The class consists of 440 fans and they have decided to let phazers run with us also.
I cleaned up the transfers and raised the exhaust ports from 30mm to 28mm. The crank has been trued and balanced. I'm going to run a set of pipes from Koch Performance and I'm thinking of having someone reshape and modify the heads over the summer. I have the rack carbs off of a v-max 600 (38mm) and Cr-125 vforce 3 reeds. I just have to find a way to mount the carbs. I can't find a carb boot to work unless I make an adapter.
I'm looking to make around 60 to 70 hp. The class consists of 440 fans and they have decided to let phazers run with us also.
Where may i ask are you going to race that they are going to let the phazers run? Thanks Rich.
Rich,
Lucky Thumb and Elkton this last year and since Elkton isn't looking to have the races up there anymore it will be somewhere else? They let the phazers run in the stock 440 fan class as well. It is speculative whether it will be the same for next year. Wait and see I guess.
Lucky Thumb and Elkton this last year and since Elkton isn't looking to have the races up there anymore it will be somewhere else? They let the phazers run in the stock 440 fan class as well. It is speculative whether it will be the same for next year. Wait and see I guess.
ok thanks if you find out later for sure where it will be, can you post it? Thanks Rich.
opsled
Active member
If you have to run against Phazers your in trouble. They will kick yer ....
To even the score run a Phazer top end on your Exciter. You will then have an eqaul playing field if not an advantage.
Good Luck, opsled
To even the score run a Phazer top end on your Exciter. You will then have an eqaul playing field if not an advantage.
Good Luck, opsled
I have a phazer so i thought i might give it a try.
A friend of mine won the stock 440 fan class on an 78 exciter. Ran against 3 phazers. Once the phazers got the handling setup right they were a couple sled lengths behind at the finish but could never beat him.
Yes I thought of that, phazer cylinders on my exciter and that will be the next step but i'm going to try this setup first. The phazer is a heavier sled so we'll see. Not to worried about it right now.
Rich, i'll let you know through this forum or PM you when we get the rules for next year.
Yes I thought of that, phazer cylinders on my exciter and that will be the next step but i'm going to try this setup first. The phazer is a heavier sled so we'll see. Not to worried about it right now.
Rich, i'll let you know through this forum or PM you when we get the rules for next year.
Opsled, I know the phazers have a displacement advantage but I have already spent so much time and money to scrap this setup just yet. Brad, #99, won every race against some phazers in the stock 440 fan class. There weren't any in the Mod class this year but next year I think some will be there.
The mod class was mostly made up of Exciters and a couple Merc Trailtwisters.
If my sled is close to the front runners I'll be happy. Its is just a blast going and seeing the vintage sleds race period.
Till next year!
The mod class was mostly made up of Exciters and a couple Merc Trailtwisters.
If my sled is close to the front runners I'll be happy. Its is just a blast going and seeing the vintage sleds race period.
Till next year!Sounds good thanks rich.