Alot of boaters in my area have the same cold start problem I have. First start of the day difficult if not impossible unless engine is run every week. All normal start procedures ie bulb priming, throttle not off idle position,performed as per operators manual. All starts after warm up are instantaeous. My last 90 yamaha with manual choke never problematic. This 2000 model ify since new.Anyone else having this difficulty? Anyone heard of a cure?
Thanks for the reply Fred. It's a two stroke. Similar postings appear in the archives for other engines, but I suspect that the wax bulb enrichment circuit in this 90 hp two stroke is a whole different animal than the four stoke engines. Before I R&R the carbs, check float level,etc. I was hoping that someone had an even more basic starting point to resolve this incredibly frustrating condition. I still have my old 90 Yammie and I am tempted to look into retrofitting the old carbs and choke system onto the newer motor.
its a little red lever located on the electric choke. there should be a corresponding decal to tell you the correct orientation. take the cowl off and look in the area of the carburettors.
Verifying the repair beyond a doubt in cold and windy weather is difficult but I think I resolved my hard start! Because of concerns about contamination reaching the carbs, I installed a 40 micron in line fuel filter and on a whim decided to replace the adjacent bulb that you pump on start up ($16.00 for both). I suspect that the check valves in the old bulb allowed the carbs to drain back to the tank after a few days of sitting. The new bulb becomes completley turgid within one or two pumps - no remarks please!!- where the old one remained very slightly mushy. The degree of mushyness did not raise the suspicions of the dealership technicians on two previous repair attempts so I guess I should'nt feel too bad about my diagnostic abilities. Back to basics and start with the easiest and cheapest first. Hope this helps others that may have the same problem. I suffered with it for 2 years.
Common problems with that Yamaha Prime Start system are fuel deposits in the primer section that sometimes also cause the plunger needle to stick and the wax element itself.Sometimes you can get it working better by removing the plunger assembly and putting it in the freezer for several hours. Measure the length of the plunger, then hook it up to a 12 volt battery and watch the plunger extend as the wax heats up inside. Let it cool, then re-install in the motor.
msd58.... I thought the bulb was replaced along with the fuel hose when the fibreglass fuel tank delaminated and trashed the fuel system in 2002 but at this point I can't be certain. I had an R&R and D&A on the carbs. tank replacment and fuel hose exchanged at that time. As an aside.. Pate makes a fine fuel tank for the Boston Whaler but the life expectancy is 10 years and I can tell you from experience you don't want to wait until it comes apart internally to replace it. No leaks - just gunk that trashes the fuel system and if that trash reaches a high speed jet you'll burn a piston. I was lucky.
seahorse.... Great input! I was hoping that someone that had familiarity with this system would post. I've had the carbs off and cleaned them with compressed air, Inspected float needles and seats etc. and I like the idea of working the plunger assembly as you described. I did have one question though... If I recall correctly, the enrichment module was on the center carb. How does it influence the upper and lower carb mixtures? Does the system just enrich the center one and count on diffusion within the crankcase to even things out?
You will see a gray hose that comes out of the area by the plunger. It goes into the intake manifold by #1 carb and there are machined passageways that will allow the fuel to flow to all 3 reed blocks.
Much appreciated Seahorse. That info filled the knowledge gap. Bulb replacment has seemed to be the remedy in my case so far. I thank you for the professional insight.
msd58... Sweet! Nearly identical to my '85 Montauk. Best boat I've ever owned. Ours has been in the family since new and I have no desire to "upgrade" to bigger, faster and higher operating costs. If the group will forgive an off topic question, was the dive platform installation a bear?
I don't have a swim step on my boat. I think what you see it a piece of rope that looks like the handle on a swim step. They look easy to put on. Try:http://continuouswave.com/cgi-bin/Ul...i?action=introFor more info
My mistake. I've seen the posts on continuouswave...great site. The wood diagram shows a small block on either side of the wood in the center of the transom where the motor mounts but the odd contour of the transom and general lack of wood in the area requires most owners to either spread the mounting stress over a larger area with oversized fender style washers on the inside of the hull or to insert additional wood discs inside the foam sandwich parts of the transom. I guess I'll either keep climbing onboard using the engine as a ladder or look into the removable center post ladder that clips on to the transom.Thanks to all for the responses.
msd58 That looks like the hot set up. Windline seems to make the best stuff out there and I have seen that ladder but didn't know if it would tend to curl underneath the boat since it has no stand offs and a pretty wide hook at the top. Does it stay where you need it while boarding?
It comes with stand offs. You can place them were you need them. I use the ladder at mid ships between the side rail and the bow rails. Basicly right at the center console area. Works fine.
I thank you for that info. There is no substitute for first hand experience. That's the beauty of these message boards. The placement of the ladder where you described would also preclude one from taking off with the ladder still out. I'm sold. It's my next purchase. Happy Holidays
auto choke-cold start prob 90 hp yamaha
Anyone heard of a cure?
Linear Mode
