Mikuni BN46I Injector Test

[val-e-vue]

I have a pair of 99 GTX Limited skis with the 951 engine. I'm in the middle of rebuilding them since both had blown engines. In the process of rebuilding carburetors I've found an anomaly with the injectors. The shop manual provides a test for the injectors, that involves connecting a pump to the injector and pumping it up until it releases. It should release around 13 psi. One of mine does exactly that and the others all release at 3 psi. Below I have included a couple photos 1) The injector 2) My test setup.

I have video of the test but I'm new here and you need to have three posts before you can post a link.

My question is: Are the injectors serviceable? If so what is the proper way to remove and disassemble. The test is covered in the shop manual but there are no service instructions. I have also looked at Mikuni document for the BN44 and it was not covered. I don't want to break anything

Thanks!!

 

[MoDawg73]

Val,
You may want to check this out. I have the same ski. It is a BN46i carb, not a 44

As to how it will affect your ski or how to repair, I can’t help you there. Sorry.

 

[val-e-vue]

Hey MoDawg, Thanks for the tip, it may lead to the answer.

 

[val-e-vue]

I updated the thread name to reflect BN46I. Not sure how I got that wrong, since my carburetor kits clearly state BN46I. If anyone has experience with the injectors, please let me know.

 

[mikidymac]

Just remove the rubber hose from them and spray carb cleaner through them. THere isn't anything to test. Either they pass fuel or they are plugged and don't/

 

[val-e-vue]

I have blown both air and carb cleaner through the nozzles. All four nozzles have good check valve action, meaning I can pull a vacuum. However only 1 of 4 carbs that I own has the prescribed 13 +/-3 psi forward release pressure. The test that I described in my opening post is taken from the shop manual Engine -> Carburetor PG 186. It may be very normal for these older carbs to develop this problem, but it sure would be nice to know how to service.

Now you might wonder, "why do you care if the nozzle develops a 13 psi forward pressure before releasing?". I believe they were trying to develop a spray pressure that was more of a blast than a trickle.

Besides that, I'm waiting to get my cylinders back from Full Bore and waiting to get cases back from a welder, so I have time to sort out some of the mysteries

 

[mikidymac]

Like I said, as long as they squirt fuel they will be fine.