RX-1 McXpress trouble

[Rpex-1]

Hello
I just picked up an 03 RX-1 With an McXpress turbo kit on it. I am having fueling issues (not enough) and tore into it to find the problem. Ends up the 30A fuse for the electric fuel pump was burnt. I installed a new fuse and burnt it as I pluged it in. I believe the wires going to the fuel pump relay are possibly pluged in wrong? Does anyone have a wiring diagram for the fuel pump and relay. I'm not familiar with these sleds or turbos for that matter. And since I bought the Rpex off the builders widow I have very little info on this machine. Any help would be greatly appreciated. Thanks.

 

[Rpex-1]

Ok update on my fueling issue. I was right. Someone switched the signal wire from the hobbs switch and the ground wire on the relay. Now it runs but seems rich. It is alright on the bottom but starts poping and gargling when I start building boost. If I hold it wide open it clears up and takes off and runs good untill I let off the throttle. It smells real rich when idling and when I start it when the engine is warm I have to give it throttle to get it to fire back up. Also when I shut it off it sometimes backfires.

 

[givemeaboost]

Do you have a good quality wide band air/fuel gauge on it ? If not put one on. It's the best way to tune a turboed sled. I would also suggest doing a compression test on it. These sleds don't take much to burn a piston or cylinder wall under boost if things aren't fueled right.


Ken...............

 

[Rpex-1]

Do you have a good quality wide band air/fuel gauge on it ? If not put one on. It's the best way to tune a turboed sled. I would also suggest doing a compression test on it. These sleds don't take much to burn a piston or cylinder wall under boost if things aren't fueled right.


Ken...............

 

[Rpex-1]

I don't have an afr guage at all. I'll order one. I'll try checking the compression too thanks.

 

[Rpex-1]

Update: I Changed out the fuel thinking I had a bad batch and added a fuel additive for extra measure. Then I tore the pulse pumps apart and rebuilt them with the Windrosa rebuild kit. The sled seems to be running pretty good now but starts hard when cold but I suppose that's normal for a 4 stroke.

 

[BigDog05]

I think I'm missing something. When you say "pulse pumps", do you mean the two factory fuel pumps?On my Bender Stage 2, the stock pumps are blocked off. Run only the electric pump. I always thought the two kits were very similar. Turbos are on opposite sides, but set up is similar. Sorry if I'm creating confusion.

 

[Rpex-1]

My electric pump is set up on a Hobbs switch that is set to turn on when I get 2lbs of boost. So with less then 2lbs of boost the fuel is supplied by the stock yamaha puls pumps and over 2lbs of boost fuel is supplied by the electric fuel pump. They did this so when you flip the machine the electric pump wont stay on and fill your engine with fuel. I was told the Hobbs switch and relay where added after and not supplied by MCXpress.

 

[BigDog05]

I see what you are saying. But can you Block off the factory pumps, and run only the electric pump ? Disconnect the hobbs switch, and see if the sled runs better on only the electric pump. My sled will run 50-60 mph at almost no boost. Just wondering if there is some sort of problem when the sled switches from vacuum pumps to electric pump. Could it be raising or lowering the float levels too much? Also do you have one hose running from the inner cooler to the slides? That would be one hose to a T and then 2 hoses from the T to each pair of carbs.That caused a lot of problems early on. The slides do not open at the same time. I think the guy went by spray25. He was one of the first to install a MCX on a 03-04 RX-1. He discovered that if you run two hoses from the innercooler to the carb slides, they would open all at the same time. One hose to each pair of carbs.

 

[BigDog05]

Rpex-1 : This is a post that may interest you. http://ty4stroke.com/threads/problem-with-bender-turbo.25515/
If you get some time, do a search under turbo section. Just put in' Bender ' under search. Lots of old stuff, but may help you get a better feel for the turbo. Some of the guys on here, really worked the bugs out of the early turbos.

 

[Buckeye]

I have a 2003 RX-1 with the MCXpress turbo and it does not use the stock fuel pumps. It only runs with the electric fuel pimp which came with the kit! This is per the instructions that came with the kit.